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