Kroeber, E., & Wolff, W. H. (1957). Biology: Comprehensive tests. D. C. Heath and Co..
Lua i Stíl Chicago (17ú heag.)Kroeber, Elsbeth, agus Walter H. Wolff. Biology: Comprehensive Tests. Boston: D. C. Heath and Co., 1957.
Lua MLA (8ú heag.)Kroeber, Elsbeth, agus Walter H. Wolff. Biology: Comprehensive Tests. D. C. Heath and Co., 1957.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.