Mcknight, T. L. (1990). Physical geography: A landscape appreciation (3rd ed.). Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Mcknight, Tom L. Physical Geography: A Landscape Appreciation. 3rd ed. Englewood Cliffs, N.J: Prentice-Hall, 1990.
Lua MLA (9ú heag.)Mcknight, Tom L. Physical Geography: A Landscape Appreciation. 3rd ed. Prentice-Hall, 1990.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.