diff --git a/application/src/Domain/SourceManagement/SourceMemberInformation.php b/application/src/Domain/SourceManagement/SourceMemberInformation.php
new file mode 100644
index 0000000..46ac8ee
--- /dev/null
+++ b/application/src/Domain/SourceManagement/SourceMemberInformation.php
@@ -0,0 +1,43 @@
+<?php
+
+namespace App\Domain\SourceManagement;
+
+use Doctrine\Common\Collections\Collection;
+use App\Entity\Source\SourceInterface;
+use Doctrine\Common\Collections\ArrayCollection;
+
+final class SourceMemberInformation implements SourceMemberInformationInterface
+{
+    /**
+     * @var SourceInterface
+     */
+    private $source;
+
+    /**
+     * @var Collection|SourceInterface[]
+     */
+    private $members;
+
+    public function __construct(SourceInterface $source)
+    {
+        $this->source = $source;
+    }
+
+    private function itterateOverMembers(Collection $members): void
+    {
+        foreach ($members as $member) {
+            if (!$this->members->contains($member)) {
+                $this->members->add($member);
+                $this->itterateOverMembers($member->getMemberRelation()->getMembers());
+            }
+        }
+    }
+
+    public function getAllMembers(): Collection
+    {
+        $this->members = new ArrayCollection();
+        $this->itterateOverMembers($this->source->getMemberRelation()->getMembers());
+
+        return $this->members;
+    }
+}
diff --git a/application/src/Domain/SourceManagement/SourceMemberInformationInterface.php b/application/src/Domain/SourceManagement/SourceMemberInformationInterface.php
new file mode 100644
index 0000000..093b3f4
--- /dev/null
+++ b/application/src/Domain/SourceManagement/SourceMemberInformationInterface.php
@@ -0,0 +1,14 @@
+<?php
+
+namespace App\Domain\SourceManagement;
+
+use Doctrine\Common\Collections\Collection;
+use App\Entity\Source\SourceInterface;
+
+interface SourceMemberInformationInterface
+{
+    /**
+     * @return Collection|SourceInterface[] All Members which belong to a source
+     */
+    public function getAllMembers(): Collection;
+}
diff --git a/application/src/Domain/SourceManagement/SourceMembershipInformation.php b/application/src/Domain/SourceManagement/SourceMembershipInformation.php
index df233f6..e3ee3f0 100644
--- a/application/src/Domain/SourceManagement/SourceMembershipInformation.php
+++ b/application/src/Domain/SourceManagement/SourceMembershipInformation.php
@@ -6,7 +6,7 @@ use Doctrine\Common\Collections\Collection;
 use App\Entity\Source\SourceInterface;
 use Doctrine\Common\Collections\ArrayCollection;
 
-class SourceMembershipInformation implements SourceMembershipInformationInterface
+final class SourceMembershipInformation implements SourceMembershipInformationInterface
 {
     /**
      * @var SourceInterface
@@ -14,7 +14,7 @@ class SourceMembershipInformation implements SourceMembershipInformationInterfac
     private $source;
 
     /**
-     * @var Collection
+     * @var Collection|SourceInterface[]
      */
     private $memberships;
 
diff --git a/application/src/Domain/SourceManagement/SourceMembershipInformationInterface.php b/application/src/Domain/SourceManagement/SourceMembershipInformationInterface.php
index c5587c3..f1c738c 100644
--- a/application/src/Domain/SourceManagement/SourceMembershipInformationInterface.php
+++ b/application/src/Domain/SourceManagement/SourceMembershipInformationInterface.php
@@ -3,8 +3,12 @@
 namespace App\Domain\SourceManagement;
 
 use Doctrine\Common\Collections\Collection;
+use App\Entity\Source\SourceInterface;
 
 interface SourceMembershipInformationInterface
 {
+    /**
+     * @return Collection|SourceInterface[] all Sources which a Source belongs to
+     */
     public function getAllMemberships(): Collection;
 }
diff --git a/application/src/Entity/Source/AbstractSource.php b/application/src/Entity/Source/AbstractSource.php
index 94cfd1d..578d40b 100644
--- a/application/src/Entity/Source/AbstractSource.php
+++ b/application/src/Entity/Source/AbstractSource.php
@@ -8,7 +8,6 @@ use App\Entity\AbstractEntity;
 use App\Entity\Attribut\LawAttribut;
 use App\Entity\Meta\LawInterface;
 use App\Entity\Meta\Law;
-use Doctrine\Common\Collections\ArrayCollection;
 use App\Entity\Attribut\SlugAttribut;
 use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity;
 use Symfony\Component\Validator\Constraints as Assert;
@@ -17,6 +16,7 @@ use App\Entity\Meta\Relation\Parent\CreatorRelationInterface;
 use App\Entity\Meta\Relation\Parent\CreatorRelation;
 use App\Entity\Attribut\MemberRelationAttribut;
 use App\Entity\Meta\Relation\Member\MemberRelation;
+use App\Entity\Meta\Relation\Member\MemberRelationInterface;
 
 /**
  * @author kevinfrantz
@@ -68,7 +68,7 @@ abstract class AbstractSource extends AbstractEntity implements SourceInterface
     protected $creatorRelation;
 
     /**
-     * @var CreatorRelationInterface
+     * @var MemberRelationInterface
      * @ORM\OneToOne(targetEntity="App\Entity\Meta\Relation\Member\MemberRelation",cascade={"persist", "remove"})
      * @ORM\JoinColumn(name="member_relation_id", referencedColumnName="id", onDelete="CASCADE")
      * @Exclude
@@ -92,11 +92,5 @@ abstract class AbstractSource extends AbstractEntity implements SourceInterface
         $this->memberRelation->setSource($this);
         $this->law = new Law();
         $this->law->setSource($this);
-        /*
-         *
-         * @todo Refactor the following attibutes
-         */
-        $this->memberships = new ArrayCollection();
-        $this->members = new ArrayCollection();
     }
 }
diff --git a/application/tests/Unit/Domain/SourceManagement/SourceMemberInformationTest.php b/application/tests/Unit/Domain/SourceManagement/SourceMemberInformationTest.php
new file mode 100644
index 0000000..f57319a
--- /dev/null
+++ b/application/tests/Unit/Domain/SourceManagement/SourceMemberInformationTest.php
@@ -0,0 +1,57 @@
+<?php
+
+namespace Tests\Unit\Domain\SourceManagement;
+
+use PHPUnit\Framework\TestCase;
+use App\Entity\Source\SourceInterface;
+use App\Entity\Source\Complex\UserSource;
+use App\Entity\Source\Primitive\Text\TextSource;
+use App\Entity\Source\Primitive\Name\FirstNameSource;
+use Doctrine\Common\Collections\ArrayCollection;
+use App\Entity\Source\Complex\FullPersonNameSource;
+use App\Domain\SourceManagement\SourceMemberInformation;
+use App\Domain\SourceManagement\SourceMemberInformationInterface;
+
+class SourceMemberInformationTest extends TestCase
+{
+    /**
+     * @var SourceInterface
+     */
+    protected $source;
+
+    /**
+     * @var SourceMemberInformationInterface
+     */
+    protected $sourceMemberInformation;
+
+    public function setUp(): void
+    {
+        $this->source = new UserSource();
+        $this->sourceMemberInformation = new SourceMemberInformation($this->source);
+    }
+
+    public function testOneDimension(): void
+    {
+        $this->source->getMemberRelation()->getMembers()->add(new TextSource());
+        $this->assertEquals(1, $this->sourceMemberInformation->getAllMembers()->count());
+    }
+
+    public function testThreeDimension(): void
+    {
+        $source1 = new TextSource();
+        $source2 = new FirstNameSource();
+        $source2->getMemberRelation()->setMembers(new ArrayCollection([$source1]));
+        $source3 = new FullPersonNameSource();
+        $source3->getMemberRelation()->getMembers()->add($source2);
+        $this->source->getMemberRelation()->getMembers()->add($source3);
+        $this->assertEquals(3, $this->sourceMemberInformation->getAllMembers()->count());
+    }
+
+    public function testRecursion(): void
+    {
+        $recursiveSource = new UserSource();
+        $recursiveSource->getMemberRelation()->getMembers()->add($this->source);
+        $this->source->getMemberRelation()->getMembers()->add($recursiveSource);
+        $this->assertEquals(2, $this->sourceMemberInformation->getAllMembers()->count());
+    }
+}