APA (7th ed.) Zitazioa
Hawking, S. (1993). Black holes and baby universes and other essays. Bantam Books.
Chicago Style (17th ed.) Zitazioa
Hawking, Stephen. Black Holes and Baby Universes and Other Essays. New York, N.Y.: Bantam Books, 1993.
MLA (9th ed.) Zitazioa
Hawking, Stephen. Black Holes and Baby Universes and Other Essays. Bantam Books, 1993.
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