(3fXQGJ aj GdJQGK GddZhj GdYQHj (B/s - (3GdegjQj, YHO GdbGOQs ((3HjQhJ (B:s (3OGQ GdZQH GdESdGej,s, 1993)
(3cTGaGJ (B: (3U(B. 249-256.s
(3HHdjhLQGajI (B: (3U(B. 245-248.s
Keywords: (3GddZI GdYQHjIs -- (3JGQjNs; (3GdJQGK GdYQHjs