Only variables can be passed by reference in wordpress
Подробные видеоинструкции Wordpress на тему: "Only variables can be passed by reference in wordpress":
Wordpress: get_page() - Only variables can be passed by reference (2 Solutions!!)
Wordpress: user_id error: Only variables should be passed by reference
Notice Only variables should be passed by reference in php:(Fixed)
Only variables can be passed by reference - PHP
