Around the bibliography. The mathematics textbook of Henan University, also known as the reference book and designated bibliography for postgraduate entrance examination of Henan University, is the most important material in the review process of specialized courses. Postgraduate entrance examination is a highly targeted examination item. The bibliography is formulated by the graduate school of the institution, and the examination content is basically around the bibliography, while most professional courses are set by the institution itself, so it is highly operable and targeted.