(3GdbGfhf GdOSJhQj GdfXe GdSjGSjI GdebGQfI (B:s (3GdfXQjI GdYGeI (B-(3WQb eeGQSI GdSdWI(B((3GdLRA GdGhd(B) /s - (3HhGdTYjQ, SYjOs ((3GdLRGFQ (B:s (3GdeDSSI GdhWfjI ddcJGH ,s, 1989)
Keywords: (3GdLRGFQs; (3GdbGfhf GdOSJhQjs; (3GdfXe GdSjGSjIs