MOVING to: https://ourbigbook.com Mission: live in a world where you can learn university-level mathematics, physics, chemistry, biology and engineering for free whenever you want from perfect open source books made for free by random people who want to get famous to get better paying jobs. 使命：生活在一个世界上，您可以随时随地免费获得完全随机的，希望成 - View it on GitHub