Roberts, J. L. (1982). Introduction to geological maps and structures. Pergamon Press.
Lua i Stíl Chicago (17ú heag.)Roberts, John Lenox. Introduction to Geological Maps and Structures. Oxford New York: Pergamon Press, 1982.
Lua MLA (9ú heag.)Roberts, John Lenox. Introduction to Geological Maps and Structures. Pergamon Press, 1982.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.