$1!9(!1J(B: $1!=Y!C*'K^'bV'Ul(B. $1'9$!_jKNg!5=s - $1!:g'D&!9Z(B. $1'V*!bh!Bds ($1'U<'V1!3K!JH!Nas, 1988)
Keywords: $1'_U!=Y(B--$1!HR'6>s