(3GdbGfhf GdLhj (B/s - (3GdYQjfj, eMeO aQjO(B.s ((3GdEScfOQjI, eUQ (B:s (3OGQ GdeWHhYGJ GdLGeYjI,s, 1987)
Keywords: (3GdbGfhf GdLhjs; (3Gdfbd GdLhjs -- (3bhGfjf hJTQjYGJs