Guttman, B. S., & Hopkins, J. W. (1983). Understanding biology. Harcourt Jovanovich.
Chicago-čujuhus (17. p.)Guttman, Burton S., juo Johns W. Hopkins. Understanding Biology. New York: Harcourt Jovanovich, 1983.
MLA-čujuhus (9. p.)Guttman, Burton S., juo Johns W. Hopkins. Understanding Biology. Harcourt Jovanovich, 1983.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.