Gaya APA

Aguilar, J, E, S, , J. (2005). The New Encyclopaedia Britannica Volume 21 . Cambridge, Mass: Prentice Hall.

Gaya MLA

Aguilar, Jacob, E., Safira,, , Jorge. "The New Encyclopaedia Britannica Volume 21". Cambridge, Mass: Prentice Hall, 2005. Text.