For the first round of review, I recommend Wang Shian's pink edition of High Numbers and Probability. Compared with Lao Li's Zhenghong, I feel that the knowledge points are not as comprehensive as the powder comb system (you can compare them yourself). At the same time, using Zhang Yu's high number 18 as an aid, many of the above methods are well summarized. Linear algebra is undoubtedly Lao Li's lecture notes on line generation, and it is basically no problem to do it several times with his video of line generation. In addition, I have to watch Zhang Yu's enhanced video, which is very good. He asked to take notes while watching, which was very helpful for later review.