Resources
Art of Problem Solving (AoPS)
https://mathcircle.berkeley.edu/
https://www.awesomemath.org/
https://www.imomath.com/
Canada IMO training
British Math Olympiads
Yufei Zhao
Po-Shen Loh
Alex Remorov
Evan Chen
Books
The IMO Compendium: Dušan Djukić, Vladimir Janković, Ivan Matić, Nikola Petrović
Problems From the Book
, Titu Andreescu and Gabriel Dospinescu
Straight From the Book
, Titu Andreescu and Gabriel Dospinescu
110-geometry-problems-from-the IMO
, Titu Andreescu and Cosmin Pohoata
Lemmas in Olympiad Geometry
,
Titu Andreescu, Sam Korsky, and Cosmin Pohoata
The Geometry of Remarkable Elements: Points, Lines, and Circles
, Titu Andreescu, Dorin Andrica, Paul Blaga, and Dan Bränzei
The Mathematical Reflections
,
Titu Andreescu and Maxim Ignatiuc
New, Newer, and Newest Inequalities
, Titu Andreescu and Marius Stanean
118 Inequalities for Mathematics Competitions
, Titu Andreescu and Marius Stanean
113 Geometric Inequalities
, Adrian Andreescu, Titu Andreescu, and Oleg Mushkarov
Topics in Functional Equations
, Titu Andreescu, Iurie Boreico, Oleg Mushkarov, and Nikolai Nikolov
Topics in Geometric Inequalities
, Titu Andreescu and Oleg Mushkarov
Number Theory Concepts and Problems
, Titu Andreescu, Gabriel Dospinescu, and Oleg Mushkarov
A Romanian Problem Book
, Titu Andreescu and Marian Tetiva
Graphs
, Radu Bumbacea
Balkan Mathematical Olympiads
, Mircea Becheanu and Bogdan Enescu
Cuban Mathematical Olympiads,
Robert Bosch (translated by Enrique Treviño