Schaaf, F. (1991). Seeing the solar system: Telescopic projects, activities, and explorations in astronomy. Wiley.
Chicago Style aipamenaSchaaf, Fred. Seeing the Solar System: Telescopic Projects, Activities, and Explorations in Astronomy. New York: Wiley, 1991.
MLA aipamenaSchaaf, Fred. Seeing the Solar System: Telescopic Projects, Activities, and Explorations in Astronomy. Wiley, 1991.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.