(3GdCMGOjK GdbOSjg (B/ s ((3YeGf (B:s (3OGQ GdaQbGf ddfTQ h GdJhRjY,s, 1989)
(3GdeLdO jMJhj Ydi LRFjf (B[1 - 2]s
Keywords: (3GdbQBf GdcQje(B.s; (3GdJaSjQ(B.s