For beginners, the Guide to Mathematical Analysis and Problem Solving is recommended, which is moderately difficult, moderately difficult to explain and practice, and has many basic topics, which is conducive to solid basic skills. In addition, I recommend two books, Typical Problems and Methods in Mathematical Analysis by Pei and Lecture Notes on Mathematical Analysis Exercises by Peking University. The former has good examples and exercises, and it is a good book to improve the exam results, especially for the postgraduate review (there are many questions for the postgraduate entrance examination in famous schools). The latter is definitely a great book, which enriches the content of the textbook. The new proof of various counterexamples and theorems is an eye-opener. The disadvantage is that the exercises are too difficult and the tips are super simple. You still can't do it after reading the prompt, hehe. The advice given in this book is that those who really want to improve the level of mathematical analysis will turn over a few pages every day, and their level will definitely improve after one year.