Creswell, J. W. (1994). Research design qualitative & quantitative approaches. Sage.
Chicago-čujuhus (17. p.)Creswell, John W. Research Design Qualitative & Quantitative Approaches. London: Sage, 1994.
MLA-čujuhus (9. p.)Creswell, John W. Research Design Qualitative & Quantitative Approaches. Sage, 1994.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.