(3GdCdYGH GdChdeHjI (B- (3GdehShYI GdQjGVjI GdejSQI (B( 30 ) s - (3YHO GdaJGM(B. (3ESeGYjds ((3OGQ GdcJGH GdeUQjs (3GdbGgQIs, 1990)
Keywords: (3GdCdYGH GdChdeHjIs; (3GdQjGVIs