Levy , C. K. (1978). Elements of biology (2nd ed.). Addison-Wesley.
Lua i Stíl Chicago (17ú heag.)Levy , Charles K. Elements of Biology. 2nd ed. Reading, Mass: Addison-Wesley, 1978.
Lua MLA (9ú heag.)Levy , Charles K. Elements of Biology. 2nd ed. Addison-Wesley, 1978.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.