Stokes, W. L. (1966). Essentials of earth history: An introduction to historical geology. Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Stokes, William Lee. Essentials of Earth History: An Introduction to Historical Geology. Englewood Cliffs, NJ: Prentice-Hall, 1966.
Lua MLA (9ú heag.)Stokes, William Lee. Essentials of Earth History: An Introduction to Historical Geology. Prentice-Hall, 1966.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.