(3YGHQhf aj cdGe YGHQ (B: s (3ebGdGJ eNJGQI (B/ s - (3OQhjT, eMehOs ((3GdOGQ GdHjVGA (B:s (3OGQ JhHbGd ddfTQ,s, 1991)
Keywords: (3GdebGdGJ GdCOHjIs