$1!66'X\!0$!L~!a((B. $1!:j'XO!0$!L~!a((B. $1!2m!CQ!0$!L~!a(s - $1!WK!8N![w!8r'\O'Q[(B; $1!0&!L:!Cr!FM!]:'Q[(B; $1!K3!0!!K0'\O'XLs ($1!04K7os $1!<@!Vk'CU!Nas, 1994)
Keywords: $1!66'X\'Qm!_As