APA (7th ed.) Zitazioa

Koch, A. R. (1986). Economic principles: Growth and environment. Avi.

Chicago Style (17th ed.) Zitazioa

Koch, A. Robert. Economic Principles: Growth and Environment. Westport, Conn.: Avi, 1986.

MLA (9th ed.) Zitazioa

Koch, A. Robert. Economic Principles: Growth and Environment. Avi, 1986.