diff --git a/__init__.py b/__init__.py
index ff6b8fc..852ae23 100644
--- a/__init__.py
+++ b/__init__.py
@@ -4,7 +4,7 @@
 # full copyright notices and license terms.
 
 from trytond.pool import Pool
-from .asset import Asset
+from .asset import Asset, AssetSourceRel
 from .rate import Rate
 from .identifier import Identifier
 from .cron import Cron
@@ -16,6 +16,7 @@ from .diagram import GraphDef, ChartPoint
 def register():
     Pool.register(
         OnlineSource,
+        AssetSourceRel,
         Asset,
         Rate,
         Identifier,
diff --git a/asset.py b/asset.py
index c4ffab5..9c40c3d 100644
--- a/asset.py
+++ b/asset.py
@@ -78,15 +78,16 @@ class Asset(ModelSQL, ModelView):
         help='Stock market symbol'),
         'get_identifiers', searcher='search_identifier')
 
-    updtsource = fields.Many2One(string='Update Source',
-        help='Select a source for the course update.',
-        ondelete='SET NULL', model_name='investment.source')
+    updtsources = fields.Many2Many(string='Update Sources',
+        help='Select sources for the course update. The course sources are tried until a valid value has been read.',
+        relation_name='investment.asset_source_rel',
+        origin='asset', target='source')
     updtdays = fields.Selection(string='Select days', required=True,
         selection=sel_updtdays)
     updttime = fields.Time(string='Time',
         states={
-            'readonly': ~Bool(Eval('updtsource')),
-        }, depends=['updtsource'])
+            'readonly': ~Bool(Eval('updtsources')),
+        }, depends=['updtsources'])
     nextupdate = fields.Function(fields.DateTime(string='Next Update',
         readonly=True),
         'get_nextupdates', searcher='search_nextupdate')
@@ -113,12 +114,48 @@ class Asset(ModelSQL, ModelView):
         readonly=True, digits=(16,digits_percent)),
         'get_percentage_change', searcher='search_percentage')
 
+    @classmethod
+    def __register__(cls, module_name):
+        """ register and migrate
+        """
+        super(Asset, cls).__register__(module_name)
+        cls.migrate_updtsource(module_name)
+
     @classmethod
     def __setup__(cls):
         super(Asset, cls).__setup__()
         cls._order.insert(0, ('name', 'ASC'))
         cls._order.insert(0, ('date', 'DESC'))
 
+    @classmethod
+    def migrate_updtsource(cls, module_name):
+        """ replace 'updtsource' by relation
+        """
+        pool = Pool()
+        Asset2 = pool.get('investment.asset')
+
+        asset_table = Asset2.__table_handler__(module_name)
+        if asset_table.column_exist('updtsource'):
+            AssetSourceRel = pool.get('investment.asset_source_rel')
+            tab_asset = Asset2.__table__()
+            cursor = Transaction().connection.cursor()
+
+            query = tab_asset.select(
+                    tab_asset.id,
+                    tab_asset.updtsource,
+                    where = tab_asset.updtsource != None,
+                )
+            cursor.execute(*query)
+            records = cursor.fetchall()
+            to_create = [{
+                    'asset': x[0],
+                    'source': x[1],
+                } for x in records]
+
+            if len(to_create) > 0:
+                AssetSourceRel.create(to_create)
+            asset_table.drop_column('updtsource')
+
     @classmethod
     def view_attributes(cls):
         return super().view_attributes() + [
@@ -164,11 +201,11 @@ class Asset(ModelSQL, ModelView):
         """
         return 'work'
 
-    @fields.depends('updtsource', 'updttime')
-    def on_change_updtsource(self):
+    @fields.depends('updtsources', 'updttime')
+    def on_change_updtsources(self):
         """ clear time-fields
         """
-        if self.updtsource is None:
+        if len(self.updtsources) == 0:
             self.updttime = None
         else :
             self.updttime = time(11, 30)
@@ -513,15 +550,21 @@ class Asset(ModelSQL, ModelView):
         """
         pool = Pool()
         Asset = pool.get('investment.asset')
+        AssetSourceRel = pool.get('investment.asset_source_rel')
         Rate = pool.get('investment.rate')
         tab_asset = Asset.__table__()
         tab_rate = Rate.__table__()
+        tab_rel = AssetSourceRel.__table__()
         context = Transaction().context
 
         query_date = context.get('qdate', CurrentDate() - Literal(1))
 
         # get last date of rate
-        tab_date = tab_asset.join(tab_rate,
+        tab_date = tab_asset.join(tab_rel,
+                # link to asset-source-relation to check if
+                # there are online-sources set
+                condition=tab_rel.asset == tab_asset.id,
+            ).join(tab_rate,
                 condition=tab_asset.id == tab_rate.asset,
                 type_ = 'LEFT OUTER',
             ).select(
@@ -531,7 +574,6 @@ class Asset(ModelSQL, ModelView):
                 tab_asset.updttime,
                 distinct_on = [tab_asset.id],
                 order_by = [tab_asset.id, tab_rate.date.desc],
-                where=tab_asset.updtsource != None,
             )
 
         query = tab_date.select(
@@ -768,27 +810,18 @@ class Asset(ModelSQL, ModelView):
             ]):
             OnlineSource.update_rate(asset)
 
-    @classmethod
-    def create(cls, vlist):
-        """ add debit/credit
-        """
-        vlist = [x.copy() for x in vlist]
-        for values in vlist:
-            if 'updtsource' in values.keys():
-                if values['updtsource'] is None:
-                    values['updttime'] = None
-        return super(Asset, cls).create(vlist)
-
-    @classmethod
-    def write(cls, *args):
-        """ deny update if cashbook.line!='open',
-            add or update debit/credit
-        """
-        actions = iter(args)
-        for lines, values in zip(actions, actions):
-            if 'updtsource' in values.keys():
-                if values['updtsource'] is None:
-                    values['updttime'] = None
-        super(Asset, cls).write(*args)
-
 # end Asset
+
+
+class AssetSourceRel(ModelSQL):
+    'Asset Source Relation'
+    __name__ = 'investment.asset_source_rel'
+
+    source = fields.Many2One(string='Online Source', select=True,
+        required=True, model_name='investment.source',
+        ondelete='CASCADE')
+    asset = fields.Many2One(string='Asset', select=True,
+        required=True, model_name='investment.asset',
+        ondelete='CASCADE')
+
+# end AssetSourceRel
diff --git a/locale/de.po b/locale/de.po
index c100853..ac567f4 100644
--- a/locale/de.po
+++ b/locale/de.po
@@ -182,13 +182,13 @@ msgctxt "help:investment.asset,date:"
 msgid "Date of current rate"
 msgstr "Datum des aktuellen Kurses"
 
-msgctxt "field:investment.asset,updtsource:"
-msgid "Update Source"
-msgstr "Kursquelle"
+msgctxt "field:investment.asset,updtsources:"
+msgid "Update Sources"
+msgstr "Kursquellen"
 
-msgctxt "help:investment.asset,updtsource:"
-msgid "Select a source for the course update."
-msgstr "Wählen Sie eine Quelle für die Kursaktualisierung aus."
+msgctxt "help:investment.asset,updtsources:"
+msgid "Select sources for the course update. The course sources are tried until a valid value has been read."
+msgstr "Wählen Sie Quellen für die Kursaktualisierung aus. Die Kursquellen werden probiert bis ein gültiger Wert gelesen wurde."
 
 msgctxt "field:investment.asset,updttime:"
 msgid "Time"
@@ -251,6 +251,22 @@ msgid "Mon - Sun"
 msgstr "Mo - So"
 
 
+###############################
+# investment.asset-source-rel #
+###############################
+msgctxt "model:investment.asset_source_rel,name:"
+msgid "Asset Source Relation"
+msgstr "Vermögenswert Quelle Verknüpfung"
+
+msgctxt "field:investment.asset_source_rel,source:"
+msgid "Source"
+msgstr "Quelle"
+
+msgctxt "field:investment.asset_source_rel,asset:"
+msgid "Asset"
+msgstr "Vermögenswert"
+
+
 #####################
 # investment.source #
 #####################
diff --git a/locale/en.po b/locale/en.po
index 22530ee..f35f434 100644
--- a/locale/en.po
+++ b/locale/en.po
@@ -154,13 +154,13 @@ msgctxt "help:investment.asset,date:"
 msgid "Date of current rate"
 msgstr "Date of current rate"
 
-msgctxt "field:investment.asset,updtsource:"
-msgid "Update Source"
-msgstr "Update Source"
+msgctxt "field:investment.asset,updtsources:"
+msgid "Update Sources"
+msgstr "Update Sources"
 
-msgctxt "help:investment.asset,updtsource:"
-msgid "Select a source for the course update."
-msgstr "Select a source for the course update."
+msgctxt "help:investment.asset,updtsources:"
+msgid "Select sources for the course update. The course sources are tried until a valid value has been read."
+msgstr "Select sources for the course update. The course sources are tried until a valid value has been read."
 
 msgctxt "field:investment.asset,updttime:"
 msgid "Time"
@@ -222,6 +222,18 @@ msgctxt "selection:investment.asset,updtdays:"
 msgid "Mon - Sun"
 msgstr "Mon - Sun"
 
+msgctxt "model:investment.asset_source_rel,name:"
+msgid "Asset Source Relation"
+msgstr "Asset Source Relation"
+
+msgctxt "field:investment.asset_source_rel,source:"
+msgid "Source"
+msgstr "Source"
+
+msgctxt "field:investment.asset_source_rel,asset:"
+msgid "Asset"
+msgstr "Asset"
+
 msgctxt "model:investment.source,name:"
 msgid "Online Source"
 msgstr "Online Source"
diff --git a/onlinesource.py b/onlinesource.py
index 125cf6b..5f551cc 100644
--- a/onlinesource.py
+++ b/onlinesource.py
@@ -222,48 +222,56 @@ class OnlineSource(ModelSQL, ModelView):
         """
         pool = Pool()
         Rate = pool.get('investment.rate')
+        IrDate = pool.get('ir.date')
 
-        if asset.updtsource is None:
+        if len(asset.updtsources) == 0:
             return
-        rate_data = cls.read_from_website(
-                asset.updtsource,
-                isin = asset.isin,
-                nsin = asset.wkn,
-                symbol = asset.secsymb,
-            )
 
-        if len(asset.updtsource.rgxident or '') > 0:
-            # check result - same code?
-            code = rate_data.get('code', None)
-            if code:
-                asset_code = getattr(asset, {
-                        'isin': 'isin',
-                        'nsin': 'wkn',
-                        'symbol': 'secsymb',
-                    }[asset.updtsource.rgxidtype])
-                if (asset_code or '').lower() != code.lower():
-                    # fail
-                    logger.warning(
-                        'update_rate: got wrong code "%(wrong)s" - expected "%(exp)s"' % {
-                            'exp': asset_code,
-                            'wrong': code,
-                            })
-                    return False
+        for updtsource in asset.updtsources:
+            rate_data = cls.read_from_website(
+                    updtsource,
+                    isin = asset.isin,
+                    nsin = asset.wkn,
+                    symbol = asset.secsymb,
+                )
 
-        to_create = {
-            'date': rate_data.get('date', None),
-            'rate': rate_data.get('rate', None),
-            'asset': asset.id,
-            }
-        if (to_create['date'] is not None) and \
-            (to_create['rate'] is not None):
-            # check if exists
-            if Rate.search_count([
-                    ('asset.id', '=', asset.id),
-                    ('date', '=', to_create['date']),
-                ]) == 0:
-                Rate.create([to_create])
-                return True
+            if len(updtsource.rgxident or '') > 0:
+                # check result - same code?
+                code = rate_data.get('code', None)
+                if code:
+                    asset_code = getattr(asset, {
+                            'isin': 'isin',
+                            'nsin': 'wkn',
+                            'symbol': 'secsymb',
+                        }[updtsource.rgxidtype])
+                    if (asset_code or '').lower() != code.lower():
+                        # fail
+                        logger.warning(
+                            'update_rate: got wrong code "%(wrong)s" - expected "%(exp)s"' % {
+                                'exp': asset_code,
+                                'wrong': code,
+                                })
+                        continue
+
+            to_create = {
+                'date': rate_data.get('date', None),
+                'rate': rate_data.get('rate', None),
+                'asset': asset.id,
+                }
+            if (to_create['date'] is not None) and \
+                (to_create['rate'] is not None):
+                # check if exists
+                if Rate.search_count([
+                        ('asset.id', '=', asset.id),
+                        ('date', '=', to_create['date']),
+                    ]) == 0:
+                    Rate.create([to_create])
+                    return True
+                else :
+                    # if we got a record for today  - stop
+                    # otherwise try next source
+                    if to_create['date'] == IrDate.today():
+                        break
         return False
 
     def get_regex_result(self, html_text, field_name):
diff --git a/tests/test_asset.py b/tests/test_asset.py
index 1d65593..798518f 100644
--- a/tests/test_asset.py
+++ b/tests/test_asset.py
@@ -568,18 +568,19 @@ class AssetTestCase(ModuleTestCase):
             'name': 'Source 1',
             }])
 
-        self.assertEqual(asset.updtsource, None)
+        self.assertEqual(len(asset.updtsources), 0)
         self.assertEqual(asset.updttime, time(14,0))
 
-        asset.updtsource = o_source
+        asset.updtsources = [o_source]
         asset.updttime = time(10, 45)
         asset.save()
-        self.assertEqual(asset.updtsource.rec_name, 'Source 1')
+        self.assertEqual(len(asset.updtsources), 1)
+        self.assertEqual(asset.updtsources[0].rec_name, 'Source 1')
         self.assertEqual(asset.updttime, time(10, 45))
 
-        asset.updtsource = None
-        asset.on_change_updtsource()
-        self.assertEqual(asset.updtsource, None)
+        asset.updtsources = []
+        asset.on_change_updtsources()
+        self.assertEqual(len(asset.updtsources), 0)
         self.assertEqual(asset.updttime, None)
 
     @with_transaction()
@@ -606,7 +607,7 @@ class AssetTestCase(ModuleTestCase):
         Asset.write(*[
             [asset],
             {
-                'updtsource': o_source.id,
+                'updtsources': [('add', [o_source.id])],
                 'updttime': time(10, 45),
             }])
 
@@ -616,7 +617,8 @@ class AssetTestCase(ModuleTestCase):
             # re-read to make context work
             asset2, = Asset.browse([asset.id])
 
-            self.assertEqual(asset2.updtsource.rec_name, 'Source 1')
+            self.assertEqual(len(asset2.updtsources), 1)
+            self.assertEqual(asset2.updtsources[0].rec_name, 'Source 1')
             self.assertEqual(asset2.updttime, time(10, 45))
             self.assertEqual(len(asset2.rates), 0)
             # qdate = 2022-10-14 simulates existence of record at this day
@@ -643,7 +645,7 @@ class AssetTestCase(ModuleTestCase):
         self.assertEqual(len(asset.rates), 1)
 
         asset2, = Asset.browse([asset.id])
-        self.assertEqual(asset.updtsource.rec_name, 'Source 1')
+        self.assertEqual(asset.updtsources[0].rec_name, 'Source 1')
         self.assertEqual(asset.updttime, time(10, 45))
         self.assertEqual(len(asset.rates), 1)
         self.assertEqual(asset.rates[0].date, date(2022, 10, 17))
@@ -668,7 +670,7 @@ class AssetTestCase(ModuleTestCase):
         self.assertEqual(len(asset.rates), 2)
 
         asset2, = Asset.browse([asset.id])
-        self.assertEqual(asset2.updtsource.rec_name, 'Source 1')
+        self.assertEqual(asset2.updtsources[0].rec_name, 'Source 1')
         self.assertEqual(asset2.updttime, time(10, 45))
         self.assertEqual(len(asset2.rates), 2)
         self.assertEqual(asset2.rates[0].date, date(2022, 10, 18))
diff --git a/tests/test_source.py b/tests/test_source.py
index 0ce1e92..630f4be 100644
--- a/tests/test_source.py
+++ b/tests/test_source.py
@@ -64,7 +64,7 @@ class SourceTestCase(ModuleTestCase):
         Asset.write(*[
             [asset],
             {
-                'updtsource': osource.id,
+                'updtsources': [('add', [osource.id])],
             }])
 
         with Transaction().set_context({
@@ -76,7 +76,8 @@ class SourceTestCase(ModuleTestCase):
             self.assertEqual(asset2.isin, 'XC0009655157')
             self.assertEqual(asset2.secsymb, '1472977')
             self.assertEqual(asset2.updttime, time(14, 0))
-            self.assertEqual(asset2.updtsource.rec_name, 'Source 1')
+            self.assertEqual(len(asset2.updtsources), 1)
+            self.assertEqual(asset2.updtsources[0].rec_name, 'Source 1')
             self.assertEqual(asset2.updtdays, 'work')
             self.assertEqual(asset2.nextupdate, datetime(2022, 10, 3, 14, 0))
             self.assertEqual(len(asset.rates), 0)
diff --git a/view/asset_form.xml b/view/asset_form.xml
index ec517b7..081304e 100644
--- a/view/asset_form.xml
+++ b/view/asset_form.xml
@@ -57,14 +57,12 @@ full copyright notices and license terms. -->
             <field name="rates" mode="tree,form,graph"/>
         </page>
         <page id="pgupdate" col="4" string="Course Update">
-            <label name="updtsource"/>
-            <field name="updtsource"/>
             <label name="updttime"/>
             <field name="updttime"/>
-
-            <label id="labupdt" colspan="2" string=" "/>
             <label name="updtdays"/>
             <field name="updtdays"/>
+
+            <field name="updtsources" colspan="4"/>
         </page>
     </notebook>