APA (7th ed.) Zitazioa
Shu, F. H. The physical universe: An introduction to astronomy. University Science Books.
Chicago Style (17th ed.) Zitazioa
Shu, Frank H. The Physical Universe: An Introduction to Astronomy. Sausalito, EUA: University Science Books.
MLA (9th ed.) Zitazioa
Shu, Frank H. The Physical Universe: An Introduction to Astronomy. University Science Books.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.