Gaya APA

Economics. (2006). [s.l.]: [s.n.].

Gaya Chicago

Economics. . [s.l.]: [s.n.], 2006. Text.

Gaya MLA

Economics. . [s.l.]: [s.n.], 2006. Text.

Gaya Turabian

Economics. [s.l.]: [s.n.], 2006. Print.