APA (7th ed.) Zitazioa
(2018). Science & Research. Union of Scientists - Stara Zagora.
Chicago Style (17th ed.) Zitazioa
Science & Research. Union of Scientists - Stara Zagora, 2018.
MLA (9th ed.) Zitazioa
Science & Research. Union of Scientists - Stara Zagora, 2018.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.