# PHP Reference

 [https://www.geeksforgeeks.org/how-to-pass-php-variables-by-reference/](https://www.geeksforgeeks.org/how-to-pass-php-variables-by-reference/) 
  [https://viblo.asia/p/bien-variable-va-tham-chieu-reference-trong-php-bJzKm4jX59N](https://viblo.asia/p/bien-variable-va-tham-chieu-reference-trong-php-bJzKm4jX59N) 

%[https://www.elated.com/php-references/]