Hass, K. (1969). Creative salesmanship understanding essentials. George Press.
Chicago-čujuhus (17. p.)Hass, K. Creative Salesmanship Understanding Essentials. London: George Press, 1969.
MLA-čujuhus (9. p.)Hass, K. Creative Salesmanship Understanding Essentials. George Press, 1969.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.