Strahler, A. H., & Strahler, A. N. (1998). Introducing physical geography (2nd ed.). Wiley.
Lua i Stíl Chicago (17ú heag.)Strahler, Alan H., agus Arthur Newell Strahler. Introducing Physical Geography. 2nd ed. New York: Wiley, 1998.
Lua MLA (9ú heag.)Strahler, Alan H., agus Arthur Newell Strahler. Introducing Physical Geography. 2nd ed. Wiley, 1998.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.