Ouyang Guangzhong's (3rd edition) mathematical analysis, that is, Chen's book, is very classic. Almost all the mathematical analysis books in Fudan are based on it, which is relatively mature and the exercises in the back are also good. I recommend reading Chen's Mathematical Analysis (the 3rd edition of Ouyang Guangzhong). This book is also a reference textbook or mathematical analysis for most mathematics majors compiled by East China Normal University!