(3GdjghO aj GdNdjL (B: s (3OQGSI aj JGQjN GdCbdjI GdjghOjI aj efWbI GdNdjL GdYQHj (B/ s ((3GdEScfOQjI (B: s (3GdecJH GdLGeYj GdMOjK , s, 1999)
Keywords: (3GdNdjL GdYQHj, GdjghO, GdCbdjGJ, GdJGQjN GdMOjK, GdYdGbGJ GdGLJeGYjIs