Gretz, K. F. (1996). Professional selling: A consultative approach. Irwin.
Chicago-čujuhus (17. p.)Gretz, Karl F. Professional Selling: A Consultative Approach. Chicago: Irwin, 1996.
MLA-čujuhus (9. p.)Gretz, Karl F. Professional Selling: A Consultative Approach. Irwin, 1996.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.