(3JfXje GdecJHI GdeOQSjI (B: s $1 (B/ s ((3HjQhJ (B: s (3eDSSI GdQSGdI , s, 1981)
Keywords: (3GdecJHGJ GdeOQSjI, JfXje GdecJHGJ, GdJYdje hGdecJHGJs