Spector, P. E. (1981). Research designs. Sage Publications.
Chicago-čujuhus (17. p.)Spector, Paul E. Research Designs. Beverly Hills: Sage Publications, 1981.
MLA-čujuhus (9. p.)Spector, Paul E. Research Designs. Sage Publications, 1981.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.