 Complete the following phrase:  Born in the village of Stambolovo in the southwestern part of Bulgaria, Velichkov started his active sports career in sixth grade, when he joined the local cross-country skiing club. He later switched to biathlon. Velichkov participated in his first Olympics in 1980 and he debuted at the World Championship-level at the World Championships in Minsk in 1982. He also participated in the Olympics in 1984 and 1988 and the World Championships in 1983, 1985, 