APA (7th ed.) Zitazioa

Percentage of Higher Education Institutions Offering Distance Education. US Department of Education.

Chicago Style (17th ed.) Zitazioa

Percentage of Higher Education Institutions Offering Distance Education. US Department of Education.

MLA (9th ed.) Zitazioa

Percentage of Higher Education Institutions Offering Distance Education. US Department of Education.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.