(3HMQ GdOehY (B/s - (3Hf GdLhRj, YHO GdQMef Hf Ydj Hf eMeO,s 508-597 (3g`(B.s ((3ecI GdecQeI (B- (3GdSYhOjg (B:s [(3O(B. (3f (B] (3,s, 1993)
Keywords: (3GdhYX hGdEQTGOs