$1!04K7o!92'Rq!>+'Xys - $1!G:!HA!3K!JH!Na'Q['[M!\ks ($1!G:!HA!3K!JH!Nas, 1990)
Keywords: $1!;E'Xi(B--$1'Oy'X<(B; $1'L4'Rqs