Babbie, E. R. (1990). Survey research methods (2nd ed.). California.
Chicago-čujuhus (17. p.)Babbie, Earl R. Survey Research Methods. 2nd ed. Belmont: California, 1990.
MLA-čujuhus (9. p.)Babbie, Earl R. Survey Research Methods. 2nd ed. California, 1990.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.