on operating systems; Novosibirsk, September 11-20, 1972

Novosibirsk, May, 10-15, 1976.

France, October 2-8, 1978. Ershov was the head of Soviet delegation

on mathematical problems; Irkutsk, June 22-25, 1982

Topic IV of Subject VII of "Informatics" problem

Tallinn, May 14-18, 1985