Schaaf, F. (1991). Seeing the solar system: Telescopic projects, activities, and explorations in astronomy. Wiley.
Dyfyniad Arddull ChicagoSchaaf, Fred. Seeing the Solar System: Telescopic Projects, Activities, and Explorations in Astronomy. New York: Wiley, 1991.
Dyfyniad MLASchaaf, Fred. Seeing the Solar System: Telescopic Projects, Activities, and Explorations in Astronomy. Wiley, 1991.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.