(3ELQGAGJ LeY GdCOdI hOhQgG aj cTa GdLQjeI (B/s - (3GdYLQaj, Ydj Hf MGeOs ((3GdQjGV (B:s [(3GdfGTQ ZjQ eMOO(B](3,s, 1999)
(3HHdjhLQGajI (B: (3UaMI (B271-276.s
(3jTJed Ydi EQLGYGJ HHdjhLQGajI(B.s
Keywords: (3GdCOdI GdLfGFjIs -- (3GdSYhOjIs; (3GdLQjeI hGdeLQehfs -- (3GdSYhOjIs; (3GdJMbjb GdLfGFjs -- (3GdSYhOjIs