diff --git a/_ressources/db_model.dbm b/_ressources/db_model.dbm
index ae36c60..45cea09 100644
--- a/_ressources/db_model.dbm
+++ b/_ressources/db_model.dbm
@@ -3,7 +3,7 @@
 CAUTION: Do not modify this file unless you know what you are doing.
          Unexpected results may occur if the code is changed deliberately.
 -->
-<dbmodel pgmodeler-ver="0.9.2-alpha1" last-position="0,343" last-zoom="0.6" max-obj-count="20"
+<dbmodel pgmodeler-ver="0.9.2-alpha1" last-position="0,441" last-zoom="0.6" max-obj-count="21"
 	 default-owner="postgres">
 <role name="kabano"
       inherit="true"
@@ -67,7 +67,7 @@ CAUTION: Do not modify this file unless you know what you are doing.
 <table name="content_comments" layer="0" collapse-mode="2" max-obj-count="12">
 	<schema name="public"/>
 	<role name="kabano"/>
-	<position x="240" y="280"/>
+	<position x="240" y="300"/>
 	<column name="id" not-null="true" sequence="public.content_comments_sequence">
 		<type name="integer" length="0"/>
 	</column>
@@ -111,7 +111,7 @@ CAUTION: Do not modify this file unless you know what you are doing.
 <table name="content_contributors" layer="0" collapse-mode="2" max-obj-count="4">
 	<schema name="public"/>
 	<role name="kabano"/>
-	<position x="680" y="480"/>
+	<position x="680" y="500"/>
 	<column name="id" not-null="true" sequence="public.content_contributors_sequence">
 		<type name="integer" length="0"/>
 	</column>
@@ -137,7 +137,7 @@ CAUTION: Do not modify this file unless you know what you are doing.
 <table name="contents" layer="0" collapse-mode="2" max-obj-count="7">
 	<schema name="public"/>
 	<role name="kabano"/>
-	<position x="540" y="40"/>
+	<position x="540" y="60"/>
 	<column name="id" not-null="true" sequence="public.contents_sequence">
 		<type name="integer" length="0"/>
 	</column>
@@ -167,7 +167,7 @@ CAUTION: Do not modify this file unless you know what you are doing.
 <table name="locales" layer="0" collapse-mode="2" max-obj-count="3">
 	<schema name="public"/>
 	<role name="kabano"/>
-	<position x="1540" y="340"/>
+	<position x="1540" y="360"/>
 	<column name="name" not-null="true">
 		<type name="character varying" length="32"/>
 	</column>
@@ -196,7 +196,7 @@ CAUTION: Do not modify this file unless you know what you are doing.
 <table name="poi_comments" layer="0" collapse-mode="2" max-obj-count="13">
 	<schema name="public"/>
 	<role name="kabano"/>
-	<position x="240" y="660"/>
+	<position x="240" y="680"/>
 	<column name="id" not-null="true" sequence="public.poi_comments_sequence">
 		<type name="integer" length="0"/>
 	</column>
@@ -246,7 +246,7 @@ CAUTION: Do not modify this file unless you know what you are doing.
 <table name="poi_contributors" layer="0" collapse-mode="2" max-obj-count="4">
 	<schema name="public"/>
 	<role name="kabano"/>
-	<position x="720" y="800"/>
+	<position x="720" y="820"/>
 	<column name="id" not-null="true" sequence="public.poi_contributors_sequence">
 		<type name="integer" length="0"/>
 	</column>
@@ -272,7 +272,7 @@ CAUTION: Do not modify this file unless you know what you are doing.
 <table name="poi_locales" layer="0" collapse-mode="2" max-obj-count="6">
 	<schema name="public"/>
 	<role name="kabano"/>
-	<position x="700" y="1020"/>
+	<position x="700" y="1040"/>
 	<column name="id" not-null="true" default-value="nextval('poi_locales_sequence'::regclass)">
 		<type name="integer" length="0"/>
 	</column>
@@ -299,7 +299,7 @@ CAUTION: Do not modify this file unless you know what you are doing.
 <table name="sources" layer="0" collapse-mode="2" max-obj-count="7">
 	<schema name="public"/>
 	<role name="kabano"/>
-	<position x="1160" y="1260"/>
+	<position x="1160" y="1280"/>
 	<column name="id" not-null="true">
 		<type name="character varying" length="3"/>
 	</column>
@@ -344,7 +344,7 @@ CAUTION: Do not modify this file unless you know what you are doing.
 <table name="users" layer="0" collapse-mode="2" max-obj-count="15">
 	<schema name="public"/>
 	<role name="kabano"/>
-	<position x="1140" y="520"/>
+	<position x="1140" y="540"/>
 	<column name="id" not-null="true" sequence="public.users_id_sequence">
 		<type name="integer" length="0"/>
 	</column>
@@ -480,7 +480,7 @@ CAUTION: Do not modify this file unless you know what you are doing.
 <table name="content_locales" layer="0" collapse-mode="2" max-obj-count="6">
 	<schema name="public"/>
 	<role name="kabano"/>
-	<position x="1020" y="40"/>
+	<position x="1020" y="60"/>
 	<column name="id" not-null="true" sequence="public.content_locales_sequence">
 		<type name="integer" length="0"/>
 	</column>
@@ -504,7 +504,7 @@ CAUTION: Do not modify this file unless you know what you are doing.
 <table name="content_versions" layer="0" collapse-mode="2" max-obj-count="8">
 	<schema name="public"/>
 	<role name="kabano"/>
-	<position x="1500" y="20"/>
+	<position x="1500" y="40"/>
 	<column name="id" not-null="true" sequence="public.content_versions_sequence">
 		<type name="integer" length="0"/>
 	</column>
@@ -537,7 +537,7 @@ CAUTION: Do not modify this file unless you know what you are doing.
 <table name="pois" layer="0" collapse-mode="2" max-obj-count="8">
 	<schema name="public"/>
 	<role name="kabano"/>
-	<position x="160" y="1080"/>
+	<position x="160" y="1100"/>
 	<column name="id" not-null="true" sequence="public.poi_versions_sequence">
 		<type name="integer" length="0"/>
 	</column>
@@ -567,7 +567,7 @@ CAUTION: Do not modify this file unless you know what you are doing.
 <table name="poi_versions" layer="0" collapse-mode="2" max-obj-count="12">
 	<schema name="public"/>
 	<role name="kabano"/>
-	<position x="1560" y="960"/>
+	<position x="1560" y="980"/>
 	<column name="id" not-null="true" sequence="public.pois_sequence">
 		<type name="integer" length="0"/>
 	</column>
@@ -601,8 +601,8 @@ CAUTION: Do not modify this file unless you know what you are doing.
 	<constraint name="poi_versions_pkey" type="pk-constr" table="public.poi_versions">
 		<columns names="id" ref-type="src-columns"/>
 	</constraint>
-	<constraint name="poi_versions_version_key" type="uq-constr" table="public.poi_versions">
-		<columns names="version" ref-type="src-columns"/>
+	<constraint name="poi_versions_version_source_key" type="uq-constr" table="public.poi_versions">
+		<columns names="version,source_id" ref-type="src-columns"/>
 	</constraint>
 </table>
 
@@ -638,7 +638,7 @@ CAUTION: Do not modify this file unless you know what you are doing.
 <table name="poi_sources" layer="0" collapse-mode="2" max-obj-count="4">
 	<schema name="public"/>
 	<role name="kabano"/>
-	<position x="1120" y="1080"/>
+	<position x="1120" y="1100"/>
 	<column name="id" not-null="true" sequence="public.poi_sources_sequence">
 		<type name="integer" length="0"/>
 	</column>
@@ -651,6 +651,9 @@ CAUTION: Do not modify this file unless you know what you are doing.
 	<column name="author" not-null="true">
 		<type name="integer" length="0"/>
 	</column>
+	<constraint name="poi_sources_pkey" type="pk-constr" table="public.poi_sources">
+		<columns names="id" ref-type="src-columns"/>
+	</constraint>
 </table>
 
 <constraint name="content_comments_author_fkey" type="fk-constr" comparison-type="MATCH SIMPLE"
@@ -755,6 +758,12 @@ CAUTION: Do not modify this file unless you know what you are doing.
 	<columns names="id" ref-type="dst-columns"/>
 </constraint>
 
+<constraint name="poi_versions_source_fkey" type="fk-constr" comparison-type="MATCH SIMPLE"
+	 upd-action="NO ACTION" del-action="NO ACTION" ref-table="public.poi_sources" table="public.poi_versions">
+	<columns names="source_id" ref-type="src-columns"/>
+	<columns names="id" ref-type="dst-columns"/>
+</constraint>
+
 <relationship name="rel_content_comments_users" type="relfk" layer="0"
 	 src-table="public.content_comments"
 	 dst-table="public.users" reference-fk="content_comments_author_fkey"
@@ -840,4 +849,9 @@ CAUTION: Do not modify this file unless you know what you are doing.
 	 dst-table="public.content_locales" reference-fk="content_versions_locale"
 	 src-required="false" dst-required="false"/>
 
+<relationship name="rel_poi_versions_poi_sources" type="relfk" layer="0"
+	 src-table="public.poi_versions"
+	 dst-table="public.poi_sources" reference-fk="poi_versions_source_fkey"
+	 src-required="false" dst-required="false"/>
+
 </dbmodel>