Fatal error: Uncaught TypeError: implode(): Argument #2 ($array) must be of type ?array, string given in /data/lib/bibtex.lib.php:28 Stack trace: #0 /data/lib/bibtex.lib.php(28): implode() #1 /data/www/main/ref.php(10): make_bibtex() #2 {main} thrown in /data/lib/bibtex.lib.php on line 28