Freemantle, D. (1993). Incredible customer service: The final test. London: McGraw-Hill.
Trích dẫn kiểu ChicagoFreemantle, David. Incredible Customer Service: The Final Test. London: McGraw-Hill, 1993.
Deismireacht MLAFreemantle, David. Incredible Customer Service: The Final Test. London: McGraw-Hill, 1993.
Rabhadh: D'fhéadfadh nach mbeadh na deismireachtaí seo 100% cruinn i gcónaí.