Fries, C. C. (1945). Teaching and learning English as a foreign language. University of Michigan Press.
Lua i Stíl Chicago (17ú heag.)Fries, Charles Carpenter. Teaching and Learning English as a Foreign Language. Ann Arbor, MI: University of Michigan Press, 1945.
Lua MLA (9ú heag.)Fries, Charles Carpenter. Teaching and Learning English as a Foreign Language. University of Michigan Press, 1945.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.