$1'a,'1L!X$'0X!BX(B: $1'CI-;T'X['`P!_A (B($1!Os!0Q'[M(B)s - $1!UW'Qm!3K!JH'Q+'Q['[Ms ($1'a,'1L!X$'0X'U<!DC!UW!0P'Rw'^]s, 1993)
Keywords: $1!04!Oz3BD!S,(B--$1!T&!2'!K}'CUs