Which one should I buy for a complete set of recipes?

as follows

1, "20 17 Li Yongle PubMed Mathematics Formula Mystery" Li Yongle Wang Shian PubMed Mathematics Series

2. Chen Wendeng's Handbook of Mathematical Formulas for Postgraduate Entrance Examination (Second Edition).

3, "20 17 Shorthand Pocket of Mathematical Formula for Postgraduate Entrance Examination" Zhang Tongbin, editor-in-chief of Tiejun

4. The author of "20 17 Shorthand Handbag of Mathematical Formula for Postgraduate Entrance Examination" is Li Zhengyuan Fan Peihua.

5. The PDF of "Quick Check Manual of Postgraduate Entrance Examination Formula" is attached with the New Oriental online course of Teacher Zhang Yu.