Gaya APA

Correct english usage. (2008). New England: [s.n.].

Gaya Chicago

Correct english usage. Cet.1. New England: [s.n.], 2008. Text.

Gaya MLA

Correct english usage. Cet.1. New England: [s.n.], 2008. Text.

Gaya Turabian

Correct english usage. New England: [s.n.], 2008. Print.