http://www.cs.cmu.edu/~./xuerui/papers/ctr.pdf

https://plushunter.github.io/2017/07/17/%E8%AE%A1%E7%AE%97%E5%B9%BF%E5%91%8A%EF%BC%882%EF%BC%89%EF%BC%9A%E5%B9%BF%E5%91%8A%E7%82%B9%E5%87%BB%E7%8E%87%E9%A2%84%E4%BC%B0%E7%9A%84%E5%9F%BA%E6%9C%AC%E8%BF%87%E7%A8%8B/

http://blog.csdn.net/a358463121/article/details/52562940 http://blog.csdn.net/mytestmy/article/details/19088519