diff --git a/Account/Account.php b/Account/Account.php
index 0c889a5dc..ebaf8f959 100644
--- a/Account/Account.php
+++ b/Account/Account.php
@@ -144,7 +144,7 @@ class Account implements ArrayableInterface, \JsonSerializable
      * @var Localization
      * @since 1.0.0
      */
-    protected Localization $l11n;
+    protected Localization $localization;
 
     use PermissionHandlingTrait;
 
@@ -159,10 +159,10 @@ class Account implements ArrayableInterface, \JsonSerializable
      */
     public function __construct(int $id = 0)
     {
-        $this->createdAt  = new \DateTime('now');
-        $this->lastActive = new \DateTime('now');
-        $this->id         = $id;
-        $this->l11n       = new Localization();
+        $this->createdAt     = new \DateTime('now');
+        $this->lastActive    = new \DateTime('now');
+        $this->id            = $id;
+        $this->localization  = new Localization();
     }
 
     /**
@@ -188,7 +188,7 @@ class Account implements ArrayableInterface, \JsonSerializable
      */
     public function getL11n() : Localization
     {
-        return $this->l11n;
+        return $this->localization;
     }
 
     /**
@@ -231,7 +231,7 @@ class Account implements ArrayableInterface, \JsonSerializable
      */
     public function setL11n(Localization $l11n) : void
     {
-        $this->l11n = $l11n;
+        $this->localization = $l11n;
     }
 
     /**
diff --git a/DataStorage/Database/DataMapperAbstract.php b/DataStorage/Database/DataMapperAbstract.php
index a80afe22c..d3d1203e2 100644
--- a/DataStorage/Database/DataMapperAbstract.php
+++ b/DataStorage/Database/DataMapperAbstract.php
@@ -2066,7 +2066,12 @@ class DataMapperAbstract implements DataMapperInterface
                     $refProp->setAccessible(true);
                 }
 
-                $objects = $mapper::get($values, RelationType::ALL, null, $depth);
+                if (!isset(static::$hasMany[$member]['by'])) {
+                    $objects = $mapper::get($values, RelationType::ALL, null, $depth);
+                } else {
+                    $objects = $mapper::getBy($values, static::$hasMany[$member]['by'], RelationType::ALL, null, $depth);
+                }
+
                 $refProp->setValue($obj, !\is_array($objects) ? [$objects->getId() => $objects] : $objects);
 
                 if (!$accessible) {
@@ -2129,8 +2134,13 @@ class DataMapperAbstract implements DataMapperInterface
                 continue;
             }
 
-            $id    = \is_object($id) ? self::getObjectId($id) : $id;
-            $value = self::getInitialized($mapper, $id) ?? $mapper::get($id, RelationType::ALL, null, $depth);
+            $id = \is_object($id) ? self::getObjectId($id) : $id;
+
+            if (!isset(static::$ownsOne[$member]['by'])) {
+                $value = self::getInitialized($mapper, $id) ?? $mapper::get($id, RelationType::ALL, null, $depth);
+            } else {
+                $value = $mapper::getBy($id, static::$ownsOne[$member]['by'], RelationType::ALL, null, $depth);
+            }
 
             $refProp->setValue($obj, $value);
 
@@ -2507,8 +2517,8 @@ class DataMapperAbstract implements DataMapperInterface
     /**
      * Get object.
      *
-     * @param mixed  $refKey    Key
-     * @param string $ref       The field that defines the for
+     * @param mixed  $forKey    Key
+     * @param string $for       The field that defines the for
      * @param int    $relations Load relations
      * @param mixed  $fill      Object to fill
      * @param int    $depth     Relation depth
@@ -2517,10 +2527,10 @@ class DataMapperAbstract implements DataMapperInterface
      *
      * @since 1.0.0
      */
-    public static function getFor($refKey, string $ref, int $relations = RelationType::ALL, $fill = null, int $depth = 3)
+    public static function getFor($forKey, string $for, int $relations = RelationType::ALL, $fill = null, int $depth = 3)
     {
         if ($depth < 1) {
-            return $refKey;
+            return $forKey;
         }
 
         if (!isset(self::$parentMapper)) {
@@ -2529,16 +2539,68 @@ class DataMapperAbstract implements DataMapperInterface
 
         self::extend(__CLASS__);
 
-        $refKey = (array) $refKey;
+        $forKey = (array) $forKey;
         $obj    = [];
 
-        foreach ($refKey as $key => $value) {
+        foreach ($forKey as $key => $value) {
             $toLoad = [];
 
-            if (isset(static::$hasMany[$ref]) && static::$hasMany[$ref]['src'] !== null) {
-                $toLoad = self::getHasManyPrimaryKeys($value, $ref);
+            if (isset(static::$hasMany[$for]) && static::$hasMany[$for]['src'] !== null) {
+                $toLoad = self::getHasManyPrimaryKeys($value, $for);
             } else {
-                $toLoad = self::getPrimaryKeysBy($value, self::getColumnByMember($ref));
+                $toLoad = self::getPrimaryKeysBy($value, self::getColumnByMember($for));
+            }
+
+            $obj[$value] = self::get($toLoad, $relations, $fill, $depth);
+        }
+
+        $countResulsts = \count($obj);
+
+        if ($countResulsts === 0) {
+            return self::getNullModelObj();
+        } elseif ($countResulsts === 1) {
+            return \reset($obj);
+        }
+
+        return $obj;
+    }
+
+    /**
+     * Get object.
+     *
+     * @param mixed  $byKey     Key
+     * @param string $by        The field that defines the for
+     * @param int    $relations Load relations
+     * @param mixed  $fill      Object to fill
+     * @param int    $depth     Relation depth
+     *
+     * @return mixed
+     *
+     * @since 1.0.0
+     */
+    public static function getBy($byKey, string $by, int $relations = RelationType::ALL, $fill = null, int $depth = 3)
+    {
+        if ($depth < 1) {
+            return $byKey;
+        }
+
+        if (!isset(self::$parentMapper)) {
+            self::$parentMapper = static::class;
+        }
+
+        self::extend(__CLASS__);
+
+        $byKey = (array) $byKey;
+        $obj   = [];
+
+        foreach ($byKey as $key => $value) {
+            $toLoad = [];
+
+            if (isset(static::$hasMany[$by]) && static::$hasMany[$by]['src'] !== null) {
+                // todo: maybe wrong?!
+                $toLoad = self::getHasManyPrimaryKeys($value, $by);
+            } elseif (isset(static::$ownsOne[$by])) {
+                $toLoad = self::getPrimaryKeysBy($value, self::getColumnByMember($by));
             }
 
             $obj[$value] = self::get($toLoad, $relations, $fill, $depth);
diff --git a/Localization/Defaults/City.php b/Localization/Defaults/City.php
index f051a0a12..921b2c4cd 100644
--- a/Localization/Defaults/City.php
+++ b/Localization/Defaults/City.php
@@ -22,7 +22,7 @@ namespace phpOMS\Localization\Defaults;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-final class City
+class City
 {
     /**
      * City id.
diff --git a/Localization/Defaults/Country.php b/Localization/Defaults/Country.php
index a5af97ff7..2feaf1d5f 100644
--- a/Localization/Defaults/Country.php
+++ b/Localization/Defaults/Country.php
@@ -22,7 +22,7 @@ namespace phpOMS\Localization\Defaults;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-final class Country
+class Country
 {
     /**
      * Country id.
diff --git a/Localization/Defaults/Currency.php b/Localization/Defaults/Currency.php
index ee0592a5f..f151303f3 100644
--- a/Localization/Defaults/Currency.php
+++ b/Localization/Defaults/Currency.php
@@ -22,7 +22,7 @@ namespace phpOMS\Localization\Defaults;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-final class Currency
+class Currency
 {
     /**
      * Currency id.
diff --git a/Localization/Defaults/Iban.php b/Localization/Defaults/Iban.php
index 7da04a662..6c3b822aa 100644
--- a/Localization/Defaults/Iban.php
+++ b/Localization/Defaults/Iban.php
@@ -22,7 +22,7 @@ namespace phpOMS\Localization\Defaults;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-final class Iban
+class Iban
 {
     /**
      * Iban id.
diff --git a/Localization/Defaults/Language.php b/Localization/Defaults/Language.php
index 410cd214a..2e17332fe 100644
--- a/Localization/Defaults/Language.php
+++ b/Localization/Defaults/Language.php
@@ -22,7 +22,7 @@ namespace phpOMS\Localization\Defaults;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-final class Language
+class Language
 {
     /**
      * Language id.
diff --git a/Localization/Defaults/NullCity.php b/Localization/Defaults/NullCity.php
new file mode 100644
index 000000000..30d7ea10a
--- /dev/null
+++ b/Localization/Defaults/NullCity.php
@@ -0,0 +1,27 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   phpOMS\Localization\Defaults
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace phpOMS\Localization\Defaults;
+
+/**
+ * City.
+ *
+ * @package phpOMS\Localization\Defaults
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class NullCity extends City
+{
+}
diff --git a/Localization/Defaults/NullCountry.php b/Localization/Defaults/NullCountry.php
new file mode 100644
index 000000000..8f59589f8
--- /dev/null
+++ b/Localization/Defaults/NullCountry.php
@@ -0,0 +1,27 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   phpOMS\Localization\Defaults
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace phpOMS\Localization\Defaults;
+
+/**
+ * Country.
+ *
+ * @package phpOMS\Localization\Defaults
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class NullCountry extends Country
+{
+}
diff --git a/Localization/Defaults/NullCurrency.php b/Localization/Defaults/NullCurrency.php
new file mode 100644
index 000000000..aee1e1af5
--- /dev/null
+++ b/Localization/Defaults/NullCurrency.php
@@ -0,0 +1,27 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   phpOMS\Localization\Defaults
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace phpOMS\Localization\Defaults;
+
+/**
+ * Currency.
+ *
+ * @package phpOMS\Localization\Defaults
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class NullCurrency extends Currency
+{
+}
diff --git a/Localization/Defaults/NullIban.php b/Localization/Defaults/NullIban.php
new file mode 100644
index 000000000..70c993e53
--- /dev/null
+++ b/Localization/Defaults/NullIban.php
@@ -0,0 +1,27 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   phpOMS\Localization\Defaults
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace phpOMS\Localization\Defaults;
+
+/**
+ * Iban.
+ *
+ * @package phpOMS\Localization\Defaults
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class NullIban extends Iban
+{
+}
diff --git a/Localization/Defaults/NullLanguage.php b/Localization/Defaults/NullLanguage.php
new file mode 100644
index 000000000..2b0ef91d9
--- /dev/null
+++ b/Localization/Defaults/NullLanguage.php
@@ -0,0 +1,27 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   phpOMS\Localization\Defaults
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace phpOMS\Localization\Defaults;
+
+/**
+ * Language.
+ *
+ * @package phpOMS\Localization\Defaults
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class NullLanguage extends Language
+{
+}
diff --git a/Localization/Localization.php b/Localization/Localization.php
index 43f83d693..83a76052d 100644
--- a/Localization/Localization.php
+++ b/Localization/Localization.php
@@ -34,7 +34,7 @@ class Localization
      * @var string
      * @since 1.0.0
      */
-    private string $country = ISO3166TwoEnum::_USA;
+    protected string $country = ISO3166TwoEnum::_USA;
 
     /**
      * Timezone.
@@ -42,7 +42,7 @@ class Localization
      * @var string
      * @since 1.0.0
      */
-    private string $timezone = 'America/New_York';
+    protected string $timezone = 'America/New_York';
 
     /**
      * Language ISO code.
@@ -50,7 +50,7 @@ class Localization
      * @var string
      * @since 1.0.0
      */
-    private string $language = ISO639x1Enum::_EN;
+    protected string $language = ISO639x1Enum::_EN;
 
     /**
      * Currency.
@@ -58,7 +58,7 @@ class Localization
      * @var string
      * @since 1.0.0
      */
-    private string $currency = ISO4217CharEnum::_USD;
+    protected string $currency = ISO4217CharEnum::_USD;
 
     /**
      * Number format.
@@ -66,7 +66,7 @@ class Localization
      * @var string
      * @since 1.0.0
      */
-    private string $decimal = '.';
+    protected string $decimal = '.';
 
     /**
      * Number format.
@@ -74,7 +74,7 @@ class Localization
      * @var string
      * @since 1.0.0
      */
-    private string $thousands = ',';
+    protected string $thousands = ',';
 
     /**
      * Angle type.
@@ -82,7 +82,7 @@ class Localization
      * @var string
      * @since 1.0.0
      */
-    private string $angle = AngleType::DEGREE;
+    protected string $angle = AngleType::DEGREE;
 
     /**
      * Temperature type.
@@ -90,7 +90,7 @@ class Localization
      * @var string
      * @since 1.0.0
      */
-    private string $temperature = TemperatureType::CELSIUS;
+    protected string $temperature = TemperatureType::CELSIUS;
 
     /**
      * Time format.
@@ -98,7 +98,7 @@ class Localization
      * @var array<string, string>
      * @since 1.0.0
      */
-    private array $datetime = [];
+    protected array $datetime = [];
 
     /**
      * Weight.
@@ -106,7 +106,7 @@ class Localization
      * @var array<string, string>
      * @since 1.0.0
      */
-    private array $weight = [];
+    protected array $weight = [];
 
     /**
      * Speed.
@@ -114,7 +114,7 @@ class Localization
      * @var array<string, string>
      * @since 1.0.0
      */
-    private array $speed = [];
+    protected array $speed = [];
 
     /**
      * Length.
@@ -122,7 +122,7 @@ class Localization
      * @var array<string, string>
      * @since 1.0.0
      */
-    private array $length = [];
+    protected array $length = [];
 
     /**
      * Area.
@@ -130,7 +130,7 @@ class Localization
      * @var array<string, string>
      * @since 1.0.0
      */
-    private array $area = [];
+    protected array $area = [];
 
     /**
      * Volume.
@@ -138,7 +138,7 @@ class Localization
      * @var array<string, string>
      * @since 1.0.0
      */
-    private array $volume = [];
+    protected array $volume = [];
 
     /**
      * Country id.
@@ -146,7 +146,7 @@ class Localization
      * @var int
      * @since 1.0.0
      */
-    private $id = 0;
+    protected int $id = 0;
 
     /**
      * Get id
diff --git a/Localization/NullLocalization.php b/Localization/NullLocalization.php
new file mode 100644
index 000000000..771c7f454
--- /dev/null
+++ b/Localization/NullLocalization.php
@@ -0,0 +1,27 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   phpOMS\Localization
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace phpOMS\Localization;
+
+/**
+ * Localization.
+ *
+ * @package phpOMS\Localization
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class NullLocalization extends Localization
+{
+}
diff --git a/tests/Account/AccountTest.php b/tests/Account/AccountTest.php
index 3ddb4d64b..e30fb751f 100644
--- a/tests/Account/AccountTest.php
+++ b/tests/Account/AccountTest.php
@@ -63,7 +63,7 @@ class AccountTest extends \PHPUnit\Framework\TestCase
         self::assertObjectHasAttribute('groups', $account);
         self::assertObjectHasAttribute('type', $account);
         self::assertObjectHasAttribute('status', $account);
-        self::assertObjectHasAttribute('l11n', $account);
+        self::assertObjectHasAttribute('localization', $account);
     }
 
     /**