APA (7th ed.) Citation

Shafik, D. (2015). Upgrading to PHP 7 (1st edition.). O'Reilly Media, Inc..

Chicago Style (17th ed.) Citation

Shafik, Davey. Upgrading to PHP 7. 1st edition. O'Reilly Media, Inc., 2015.

MLA (9th ed.) Citation

Shafik, Davey. Upgrading to PHP 7. 1st edition. O'Reilly Media, Inc., 2015.

Warning: These citations may not always be 100% accurate.