(3GdENJHGQGJ GdYedjg h GdJWHjbjg ddMHhH h efJLGJgG (B/ s - (3eUWai, eUWai ceGds ((3GdbGgQg (B:s (3GdTQcg GdYQHjg ddfTQ h GdJhRjY,s, 1991)
Keywords: (3GdMHhHs; (3GdNHRs; (3GdObjbs