Curtis, H. (1975). Biology (2nd.ed.). Worth.
Chicago-čujuhus (17. p.)Curtis, Helena. Biology. 2nd.ed. New York: Worth, 1975.
MLA-čujuhus (9. p.)Curtis, Helena. Biology. 2nd.ed. Worth, 1975.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.