(3HZOGO aj GdTYQ GdYQHj (B: s (3ef JGQjNgG hGNHGQgG GdMVGQjI (B/ s - (3GdGdhSj , LeGd GdOjf s ((3GdYQGb (B: s (3eWHYI GdeLeY GdYdej GdYQGbj , s, 1987)
Keywords: (3GdTYQ GdYQHj s -- (3GdYQGb s