(3eUGQYI GdKjQGf (B- (3GdehShYI GdQjGVjI GdejSQI (B( 20 )s - (3YHO GdaJGM(B. (3ESeGYjds ((3OGQ GdcJGH GdeUQjs (3GdbGgQIs, 1990)
Keywords: (3eUGQYI GdKjQGf (B- (3QjGVI s; (3GdQjGVI s