(3eCSGI GdMjGI hCZfjI ddEfSGf(B: (3eWhdI TYQjI W(B2s - (3Gd(B^(3edGFcI(B. (3fGRcs ((3OGQ GdYhOIs (3HjQhJs, 1981)
Keywords: (3GdTYQ GdYQHj GdMOjKs