APA (7th ed.) Zitazioa

Timm, P. R. (1992). 50 ways to keep your customers: "and get new ones". Jack Wilson and Associates.

Chicago Style (17th ed.) Zitazioa

Timm, Paul R. 50 Ways to Keep Your Customers: "And Get New Ones". Illonois, Chicago: Jack Wilson and Associates, 1992.

MLA (9th ed.) Zitazioa

Timm, Paul R. 50 Ways to Keep Your Customers: "And Get New Ones". Jack Wilson and Associates, 1992.