Feather, R. M., Snyder, S. L., & T Hesser, D. (1993). Merrill earth science. McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Feather, Ralph M., Susan Leach Snyder, agus Dale T Hesser. Merrill Earth Science. New York: McGraw-Hill, 1993.
Lua MLA (8ú heag.)Feather, Ralph M., et al. Merrill Earth Science. McGraw-Hill, 1993.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.