Gaya APA

English Skill. (2006). New York: [s.n.].

Gaya Chicago

English Skill. . New York: [s.n.], 2006. Text.

Gaya MLA

English Skill. . New York: [s.n.], 2006. Text.

Gaya Turabian

English Skill. New York: [s.n.], 2006. Print.