(3QLd GdSjGSI (B:s (3GdCSS GdGLJeGYjI ddSjGSI (B/s - (3SjehQ, eGQJf djHSJs ((3HjQhJ (B:s (3OGQ GdBaGb GdLOjOI ,s, 1960)
Keywords: (3GdGLQGAGJ GdSjGSjIs; (3GdGfJNGHGJ s; (3GdOjebQGWjI s; (3Yde GdGLJeGY GdSjGSj s