$1'W$!OY!;E'Xls - $1K7o'YX!BX!4H!3K!JH!Na'Q['[M!\ks ($1K7o'YX!BX!4H!3K!JH!Nas, 1987)
Keywords: $1!DU!X7(B; $1!P2!X7(B; $1!]>!X7s