WIERSEMA FRED. (1998). CUSTOMER SERVICE. HARPER COLLINS PUBLISHERS.
Chicago-čujuhus (17. p.)WIERSEMA FRED. CUSTOMER SERVICE. NEW YORK: HARPER COLLINS PUBLISHERS, 1998.
MLA-čujuhus (9. p.)WIERSEMA FRED. CUSTOMER SERVICE. HARPER COLLINS PUBLISHERS, 1998.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.