(2000). Expo data: Various countries. [s.n].
芝加哥风格引文Expo Data: Various Countries. [s.l]: [s.n], 2000.
MLA引文Expo Data: Various Countries. [s.n], 2000.
警告:这些引文格式不一定是100%准确.
(2000). Expo data: Various countries. [s.n].
芝加哥风格引文Expo Data: Various Countries. [s.l]: [s.n], 2000.
MLA引文Expo Data: Various Countries. [s.n], 2000.