Cita APA

Zeilik, M., & Gregory, S. A. (1998). Introductory astronomy & astrophysics (4. ed.). Belmont, Calf.: Brook/cole, Cengage Learning.

Citación estilo Chicago

Zeilik, Michael, y Stephen A. Gregory. Introductory Astronomy & Astrophysics. 4. ed. Belmont, Calf.: Brook/cole, Cengage Learning, 1998.

Cita MLA

Zeilik, Michael, y Stephen A. Gregory. Introductory Astronomy & Astrophysics. 4. ed. Belmont, Calf.: Brook/cole, Cengage Learning, 1998.