一般一元五次（及以上）方程无求根公式的直观解释（转)

http://www.360doc.com/content/24/0609/10/99071_1125725480.shtml

https://viegg.com/abel/readme.html

https://www.zhihu.com/question/29316970/answer/151839928

https://www.zhihu.com/question/534514417

https://zhuanlan.zhihu.com/p/77583443