Gaya APA

Principles of economics / Karl E. Case ; Ray C. Fair ; Sharon M. Oster. (1971). Harlow, Essex: Pearson Education, c.

Gaya MLA

Principles of economics / Karl E. Case ; Ray C. Fair ; Sharon M. Oster. 10th ed.. Harlow, Essex: Pearson Education, c, 1971. Buku Wajib.