Web Scraping in Google Scholar - php

Question

I'm trying to scrape from Google Scholar profile pages.The idea is that I want to retrieve the publications' list with an XPath but I does not download the page, here's my code:
I tried with curl
function get_page($url) {
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'GET');
//I tried to change user agent as well
//curl_setopt($ch,CURLOPT_USERAGENT,'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.13) Gecko/20080311 Firefox/2.0.0.13');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
curl_close($ch);
return $response;
}
And without curl :
function get_xpath($query_url) {
$dom = new DOMDocument();
#$dom->loadHTMLFile($query_url);
sleep(1);
return new DOMXpath($dom);
}
$query_url = "https://scholar.google.it/citations?user=p-POZjgAAAAJ&hl=it&cstart=0&pagesize=100";
To get it without curl
$xpath = get_xpath($query_url);
To get it with curl
$xpath = get_xpath(get_page($query_url));
And then
$autori=$xpath->query("//tr[1]/td[1]/div[1]");
But $autori keeps being empty, any idea?