APA (7th ed.) Zitazioa
Lewis, C. (1940). The problem of pain. Collins.
Chicago Style (17th ed.) Zitazioa
Lewis, C.S. The Problem of Pain. Collins, 1940.
MLA (9th ed.) Zitazioa
Lewis, C.S. The Problem of Pain. Collins, 1940.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.