Gaya APA
Electronic communication. (1981).
Hamburg:
McGraw Hill.
Gaya Chicago
Electronic communication.
4 th.
Hamburg:
McGraw Hill,
1981.
Reference.
Gaya MLA
Electronic communication.
4 th.
Hamburg:
McGraw Hill,
1981.
Reference.
Gaya Turabian
Electronic communication.
Hamburg:
McGraw Hill,
1981.
Reference.