Gaya APA
Economics. (1979).
:
Mcgraw-Hill Book Company.
Gaya Chicago
Economics.
Ed. 2 Rev.
:
Mcgraw-Hill Book Company,
1979.
.
Gaya MLA
Economics.
Ed. 2 Rev.
:
Mcgraw-Hill Book Company,
1979.
.
Gaya Turabian
Economics.
:
Mcgraw-Hill Book Company,
1979.
.