(3GdJYdje GdKGfhj (B: s (3JLGQH YQHjI h YGdejI (B/ s - (3GdYdhGfj, fhQj YHGS YHO Gddgs ((3HjQhJ (B:s (3GdeDSSI GdLGeYjI ddOQGSGJ hGdfTQ hGdJhRjY,s, 1991)
Keywords: (3GdJYdje GdKGfhjs