Gaya APA
Essential Chemistry. (1979).
California:
[s.n.].
Gaya Chicago
Essential Chemistry.
.
California:
[s.n.],
1979.
Text.
Gaya MLA
Essential Chemistry.
.
California:
[s.n.],
1979.
Text.
Gaya Turabian
Essential Chemistry.
California:
[s.n.],
1979.
Print.