Παραπομπή σε μορφή APA (7η εκδ.)

Knapp, D. (2015). A guide to customer service skills for the service desk professional (4th edition.). Cengage Learning.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Knapp, Donnz. A Guide to Customer Service Skills for the Service Desk Professional. 4th edition. Boston, Massachusetts: Cengage Learning, 2015.

Παραπομπή σε μορφή MLA (9th εκδ.)

Knapp, Donnz. A Guide to Customer Service Skills for the Service Desk Professional. 4th edition. Cengage Learning, 2015.