Citazione APA

Zeilik, M. S. (1987). Introductory astronomy and astrophysics (2.).

Stile di citazione Chicago

Zeilik, Michael; Smith. Introductory Astronomy and Astrophysics. 2. Saunders College Publishing, New York, 1987.

Citazione MLA

Zeilik, Michael; Smith. Introductory Astronomy and Astrophysics. 2. 1987.