排列组合常见类型与解法
https://wenku.baidu.com/view/467c12601ed9ad51f01df255.html
排列组合讲解
https://wenku.baidu.com/view/66cdddfab52acfc788ebc900.html
排列组合概率例题与讲解
https://wenku.baidu.com/view/a4e1645df4335a8102d276a20029bd64793e6258.html?rec_flag=default&sxts=1583719388554
麻将技巧秘籍
https://wenku.baidu.com/view/a7556e343968011ca300916f.html?sxts=1583719496919
为什么麻将术语中会有"对杵不如卡"这一说法?
http://dy.163.com/v2/article/detail/EA0M6CFP0518TCRK.html