Cooper,Donald R. (2011). Business Research Methods (9th.). McGraw Hill Education.
Chicago-čujuhus (17. p.)Cooper,Donald R. Business Research Methods. 9th. McGraw Hill Education, 2011.
MLA-čujuhus (9. p.)Cooper,Donald R. Business Research Methods. 9th. McGraw Hill Education, 2011.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.