APA (7th ed.) Zitazioa
Roberts, H. M. (1961). Champion of the silent billion: By Helen M. Roberts. Macalester Park Pub. Co..
Chicago Style (17th ed.) Zitazioa
Roberts, Helen M. Champion of the Silent Billion: By Helen M. Roberts. Minnesota: Macalester Park Pub. Co., 1961.
MLA (9th ed.) Zitazioa
Roberts, Helen M. Champion of the Silent Billion: By Helen M. Roberts. Macalester Park Pub. Co., 1961.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.