Gaya APA

Walstad, W, B. (2002). Study Guide to Accompany Economics Principles, Problems, and Policies (Cet. 1). Hoboken, NJ: David McKAY Company.

Gaya MLA

Walstad, William, B.. "Study Guide to Accompany Economics Principles, Problems, and Policies". Cet. 1 Hoboken, NJ: David McKAY Company, 2002. Text.