$1'HX!Bo'`[!1k'Xms - $1!K3!:k'3p!+5!;'!S,!2r'Q[!UNs ($1!04!9*!FM!Bo':`!^z!3K!JH!Nas, 1991)
Keywords: $1!5F!FM!Bo'`[!1k'Xm(B--$1'HX!Bos