Gribbin, J. (1998). Watching the Universe. Universities Press(India) Ltd.
Chicago Style aipamenaGribbin, John. Watching the Universe. Hyderabad: Universities Press(India) Ltd, 1998.
MLA aipamenaGribbin, John. Watching the Universe. Universities Press(India) Ltd, 1998.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.