RNN:CSDN https://blog.csdn.net/zhaojc1995/article/details/80572098
知乎 https://zhuanlan.zhihu.com/p/28054589
LSTM:知乎链接 https://blog.csdn.net/vbskj/article/details/71713204
CSDN https://blog.csdn.net/gzj_1101/article/details/79376798#LSTM_10
官方文档 http://deeplearning.net/tutorial/lstm.html