Need. Li Yongle's and Wang Shian's version of Review Book for Postgraduates' Mathematics is called Li Wang's Review Book, which is the most widely used review book in the postgraduate field. The knowledge covered in this book is comprehensive and basic, and many topics are typical, so it is necessary to buy a basic article on mathematics for postgraduate entrance examination. The national unified entrance examination for graduate students, referred to as "postgraduate entrance examination" and "unified examination" for short, refers to the general name of the relevant examinations organized by the education authorities and enrollment institutions for the selection of graduate students, and consists of the initial examination and re-examination organized by the national examination authorities and enrollment units.