https://blog.csdn.net/AFUL1991/article/details/79599213
手写识别数字代码详解
https://blog.csdn.net/dugudaibo/article/details/77119534
https://www.cnblogs.com/pathrough/p/5855084.html
习题一解答
https://blog.csdn.net/weixin_34319111/article/details/92180824
neural network and deep learning
原文:https://www.cnblogs.com/wwqdata/p/12409615.html