Gaya APA
Explorations:an Introduction To Astronomy. (2006).
New York:
[s.n.].
Gaya Chicago
Explorations:an Introduction To Astronomy.
.
New York:
[s.n.],
2006.
Text.
Gaya MLA
Explorations:an Introduction To Astronomy.
.
New York:
[s.n.],
2006.
Text.
Gaya Turabian
Explorations:an Introduction To Astronomy.
New York:
[s.n.],
2006.
Print.