(3OQGSGJ aj ecGaMI GdEQgGH (B/s - (3YHO GdcQje GHh GdaJhM OQhjTs ((3GdbGgQI(B:s [(3GdfGTQ ZjQ eMOO(B](3,s, 1997)
. 240-220 (3HHdjhLQGajG(B: (3UaMGJ(B.s
(3GdfU HGddZI GdYQHjIs
Keywords: (3GdJTQjY GdNGU HGdEQgGHs; (3GdbGfhf GdLfGFjs