Gaya APA
The Key to english : Letter Writing. (1977).
New York:
[s.n.].
Gaya Chicago
The Key to english : Letter Writing.
Cet.6.
New York:
[s.n.],
1977.
Text.
Gaya MLA
The Key to english : Letter Writing.
Cet.6.
New York:
[s.n.],
1977.
Text.
Gaya Turabian
The Key to english : Letter Writing.
New York:
[s.n.],
1977.
Print.