APA (7th ed.) Zitazioa
Langan, J. (2002). English skills with reading (5th ed.). McGrawHill.
Chicago Style (17th ed.) Zitazioa
Langan, Jhon. English Skills with Reading. 5th ed. New York: McGrawHill, 2002.
MLA (9th ed.) Zitazioa
Langan, Jhon. English Skills with Reading. 5th ed. McGrawHill, 2002.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.