(3Gddg h GdYde GdMOjK (B/ s - (3fhad, YHO GdQRGbs ((3GdbGgQI (B:s (3OGQ GdTQhb,s, 1990)
Keywords: (3GdESdGes; (3GdYdhes; (3GdYdhe GdESdGejIs