A PHP Error was encountered

Severity: Warning

Message: file_get_contents(https://...@utoronto.ca.[Affiliation]&datetype=edat&usehistory=y&retmax=25&tool=pubfacts&email=info@pubfacts.com&api_key=b8daa3ad693db53b1410957c26c9a51b4908): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests

Filename: helpers/my_audit_helper.php

Line Number: 144

Backtrace:

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 144
Function: file_get_contents

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 212
Function: simplexml_load_file_from_url

File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3106
Function: getPubMedXML

File: /var/www/html/application/controllers/Search.php
Line: 168
Function: pubMedSearch_Global

File: /var/www/html/index.php
Line: 316
Function: require_once