(3QGFO fUQ GdeSdejf Ydi GdUdjHjf fhQ GdOjf eMehO(B: (3SjQI eDef UGOb (B/ s - (3MSjf eDfSs ((3GdQjGV (B: s (3GdOGQ GdSYhOjI ddfTQ hGdJhRjY , s, 1987)
Keywords: (3GdGSdGe (B- (3JQGLes; (3fhQGdOjf eMehOs