Rubin,Gretchen. (2011). The Happiness trap. Harper Collins.
Chicago-čujuhus (17. p.)Rubin,Gretchen. The Happiness Trap. New York: Harper Collins, 2011.
MLA-čujuhus (9. p.)Rubin,Gretchen. The Happiness Trap. Harper Collins, 2011.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.