International Mathematical Olympiad

27th -- July 9, 1986 -- Warsaw, poland
28th -- July 10, 1987-- Havana, Cuba
29th -- Canberra, Australia
30th -- Braunschweig, Germany
31st -- July 12, 1990 -- Beijing, China

USA Mathematical Olympiad

Canadian Mathematical Olympiad

Asian Pacific Mathematical Olympiad

Kazakhstan Mathematical Olympiad

Russian Mathematical Olympiad