$content = $book->childNodes;
$authors = array();
$title = $publisher = $date = $translate = false;
foreach ($content as $node)
    switch($node->nodeName) {
        case "AUTHOR" : $authors[] = $node->nodeValue;break;
        case "TITLE" : $title = $node->nodeValue;break;
        case "PUBLISHER" : $publisher = $node->nodeValue;break;
        case "TRANSLATOR" : $translate = $node->nodeValue;break;
        case "DATEPUB" : $date = $node->nodeValue;break;
    }

$rel = "//BOOK[@ISBN="\" . $book->attributes->getNamedItem("ISBN")->nodeValue . "\"]/";
        $title = $xpath->query($rel."TITLE")->item(0)->nodeValue;
        $authors = $xpath->query($rel."AUTHOR");
        $publisher = $xpath->query($rel."PUBLISHER")->item(0)->nodeValue;
        $translate = $xpath->query($rel."TRANSLATOR")->item(0)->nodeValue;
        if(!empty($translate))
            $translate = $xpath->query($rel."TRANSLATOR")->item(0)->attributes->getNamedItem("PREFIX")->nodeValue . " " . $translate;
        $date = $xpath->query($rel."DATEPUB")->item(0)->nodeValue;