PHP object oriented programming: Exercises, Practice, Solution https://www.w3resource.com/php-exercises/oop/index.php
Creating Web APIs with Python and Flask | Programming Historian https://programminghistorian.org/en/lessons/creating-apis-with-python-and-flask#setting-up
iPhone Game Tutorial With Videos– Programming Tutorials | iPhone, iOS 4, iPad SDK Development Tutorial and Programming Tips http://maniacdev.com/2010/01/incredible-iphone-game-programming-tutorials-with-video/