Cullingford, R. (1980). Timescales in geomorphology. John Wiley and Sons.
Lua i Stíl Chicago (17ú heag.)Cullingford, R.A. Timescales in Geomorphology. New York: John Wiley and Sons, 1980.
Lua MLA (9ú heag.)Cullingford, R.A. Timescales in Geomorphology. John Wiley and Sons, 1980.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.