Beerbower, James R., & Boyer, R. E. (1971). Field guide to fossils. Houghton Mifflin.
Lua i Stíl Chicago (17ú heag.)Beerbower, James R., agus Robert E. Boyer. Field Guide to Fossils. Boston: Houghton Mifflin, 1971.
Lua MLA (9ú heag.)Beerbower, James R., agus Robert E. Boyer. Field Guide to Fossils. Houghton Mifflin, 1971.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.