$1!R;!6)(B. $1!>f!6)(B. $1'8t!6)(B: $1!04K7o!0T!9%!R;!9B'2Fs - $1!8x(RRs ($1!04!<5!5.!PN!3K!JH!Nas, 1991)
Keywords: $1!04K7o'2F'X<s