(3GdThQi (B: s (3Hjf GdfU h GdJLQHI GdJGQjNjI (B/ s - (3GdSjO, QVhGfs ((3CHh XHj (B: s (3eQcR GdCeGQGJ GdOQGSGJ h GdHMhK, s, 1997)
Keywords: (3GdThQi(B. s; (3GdCMcGe GdSdWGfjI(B. s