protected function parseMetadata( \SimpleXMLElement $xml ) {

		foreach ( $xml->metadata->children( 'dc', true ) as $key => $val ) {

			$val = (string) $val;

			// Set authors
			if ( 'creator' === $key && ! empty( $val ) ) {
				$this->authors .= trim( $val ) . ', ';
			} elseif ( 'contributor' === $key && ! empty( $val ) ) {
				$this->authors .= trim( $val ) . ', ';
			}
		}

		// Get rid of trailing comma
		$this->authors = rtrim( $this->authors, ', ' );
	}