Gaya APA

Gill, R, T. (1978). Economics : a text with readings 3rd (3rd ed.). Santa Monica, CA: Goodyear Publishing, c.

Gaya MLA

Gill, Richard, T.. "Economics : a text with readings 3rd". 3rd ed. Santa Monica, CA: Goodyear Publishing, c, 1978. Buku Wajib.