Spaulding, N. E., & Namowitz, S. N. (1994). Earth science. Heath.
Lua i Stíl Chicago (17ú heag.)Spaulding, Nancy E., agus Samuel N. Namowitz. Earth Science. Lexington, Massachusetts: Heath, 1994.
Lua MLA (9ú heag.)Spaulding, Nancy E., agus Samuel N. Namowitz. Earth Science. Heath, 1994.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.