(3GdfXQjI GdYGeI ddGdJRGe (B:s (3eUGOQ GdGdJRGe (B/s - (3SdjeGf , Ydj Ydj s ((3GdLRGFQ (B:s (3OjhGf GdeWHhYGJ GdLGeYjI ,s, 1990)
Keywords: (3GdGdJRGe s; (3GdYGeI s; (3GdfXQjI s