Gaya APA
Economic and finance. (1982).
Texas:
Society of petroleum Engineers.
Gaya Chicago
Economic and finance.
.
Texas:
Society of petroleum Engineers,
1982.
Text.
Gaya MLA
Economic and finance.
.
Texas:
Society of petroleum Engineers,
1982.
Text.
Gaya Turabian
Economic and finance.
Texas:
Society of petroleum Engineers,
1982.
Print.