private function getBooksFromAmazon($isbns, Config $config)
 {
     \Sb\Trace\Trace::addItem(count($isbns) . " Isbns vont être requetés à Amazon : " . implode(",", $isbns));
     $booksFromAmazon = array();
     for ($index = 0; $index < count($isbns); $index = $index + 10) {
         $isbnsSlice = array_slice($isbns, $index, 10);
         \Sb\Trace\Trace::addItem(count($isbnsSlice) . " Isbns requetés par requête Amazon : " . implode(",", $isbnsSlice));
         $amazonService = new Zend_Service_Amazon($config->getAmazonApiKey(), 'FR', $config->getAmazonSecretKey());
         $responsesGroups = 'Small,ItemAttributes,Images,EditorialReview,Reviews';
         // Recherche d'une liste de livre
         $amazonResults = $amazonService->itemLookup(implode(",", $isbnsSlice), array('SearchIndex' => 'Books', 'AssociateTag' => $config->getAmazonAssociateTag(), 'ResponseGroup' => $responsesGroups, 'IdType' => 'ISBN'));
         if ($amazonResults) {
             $i = 0;
             foreach ($amazonResults as $amazonResult) {
                 $result = new \Sb\Db\Model\Book();
                 \Sb\Db\Mapping\BookMapper::mapFromAmazonResult($result, $amazonResult);
                 if ($result->IsValid()) {
                     $i++;
                     $booksFromAmazon[] = $result;
                 }
                 //var_dump($booksFromAmazon);
             }
             \Sb\Trace\Trace::addItem($i . " trouvés lors de cette requête amazon.");
         }
     }
     return $booksFromAmazon;
 }