Kasmir
Etika customer service / Kasmir
RajaGrafindo Persada, 2005
 Buku Teks
Best practices in customer service
edited by Ron Zemke and John A. Woods
American Management Association, 1998
 eBooks
Anderson, Kristin
Great customer service on the telephone
American Management Association, 1992
 eBooks
Kasmir
Etika customer service
RajaGrafindo Persada, 2005
 Buku Teks
Lucas, Robert W.
Customer service : skills for success
McGrow-Hill, 2015
 Buku Teks