insights and strategies for mathematical Olympiad and competitions 几何解题策略：insights and strategies for mathematical Olympiad and competitions Probability and expectation in Mathematical Olympiad and competitions Combinatorial problems in Mathematical Olympiad and competitions Graph theory in Mathematical Olympiad and competitions Combinatorial extremization in Mathematical Olympiad and competitions Effects and strategies of international tax competition 并列题名：Effects and strategies of international tax competition Ten algebraic themes for mathematics competitions 118 inequalities for mathematics competitions