Pipkin, B., & Cummings, D. (1983). Environmental geology: Practical exercises. Star Publishing.
Lua i Stíl Chicago (17ú heag.)Pipkin, Bernard, agus David Cummings. Environmental Geology: Practical Exercises. Belmont, California: Star Publishing, 1983.
Lua MLA (9ú heag.)Pipkin, Bernard, agus David Cummings. Environmental Geology: Practical Exercises. Star Publishing, 1983.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.