Lucas, Robert W.
Customer service : skills for success
McGrow-Hill, 2015
Buku Teks
Knapp, Donna
A guide to Service desk concepts / Donna Knapp
Course Tecnology Cengage, 2014
Buku Teks
Loughary, John W.
Helping others help themselves a guide to connseling skills
McGraw-Hill, 1979
Buku Teks SO
Lucas, Robert W.
Customer service : building successful skills for the twenty-first century
McGraw-Hill, 2005
Buku Teks
Priestley, Philip
Learning to help : basic skills exercises
Tavistock, 1983
Buku Teks SO