Drubbel, B. (2003). The 21st century Webster's international encyclopedia: The new illustrated reference guide. Trident Press International.
芝加哥风格引文Drubbel, Bart. The 21st Century Webster's International Encyclopedia: The New Illustrated Reference Guide. Naples, Fla: Trident Press International, 2003.
MLA引文Drubbel, Bart. The 21st Century Webster's International Encyclopedia: The New Illustrated Reference Guide. Trident Press International, 2003.
警告：这些引文格式不一定是100％准确.