1. https://www.cnblogs.com/guoyaohua/p/8542554.html
2. https://blog.csdn.net/weixin_40170902/article/details/80092628
3.https://www.cnblogs.com/guoyaohua/p/8544835.html (指数加权平均，偏差修正)
4.https://link.jianshu.com/?t=https://arxiv.org/pdf/1609.04747.pdf （论文）
5.https://blog.csdn.net/u012328159/article/details/80311892