Cowell, D. W. (1993). Services marketing (3rd ed.). Butterworth-Heinemann.
Chicago-čujuhus (17. p.)Cowell, Donald W. Services Marketing. 3rd ed. Oxford: Butterworth-Heinemann, 1993.
MLA-čujuhus (9. p.)Cowell, Donald W. Services Marketing. 3rd ed. Butterworth-Heinemann, 1993.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.