Handbook of Mathematical Functions With Formulas, Graphs and Mathematical Tables

A Mathematical Olympiad Primer by Geoff Smith

Graph Theory: In Mathematical Olympiad And Competitions by Bin Xiong (English) P

Groups and Their Graphs by Grossman & Magnus - The MAA New Mathematical Library

Probability And Expectation: In Mathematical Olympiad And Competitions by Zun Sh

Saunders Ser.: Mathematical Logic : Application and Theory by Jean Rubin (1990)

Combinatorial Extremization: In Mathematical Olympiad And Competitions by Yuefen

Probability And Expectation (Mathematical Olympiad)