protected function getItems( array $nodes, array $ref )
	{
		$keys = [];

		foreach( $nodes as $node )
		{
			if( ( $attr = $node->attributes->getNamedItem( 'ref' ) ) !== null ) {
				$keys[] = $attr->nodeValue;
			}
		}

		$manager = \Aimeos\MShop::create( $this->getContext(), 'attribute' );
		$search = $manager->createSearch()->setSlice( 0, count( $keys ) );
		$search->setConditions( $search->compare( '==', 'attribute.key', $keys ) );

		return $manager->searchItems( $search, $ref );
	}