Levy ,Charles Kingsley. (1979). Biology: Human perspectives. Goodyear.
Chicago-čujuhus (17. p.)Levy ,Charles Kingsley. Biology: Human Perspectives. Santa Monica, California: Goodyear, 1979.
MLA-čujuhus (9. p.)Levy ,Charles Kingsley. Biology: Human Perspectives. Goodyear, 1979.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.