Gaya APA
Economics. (1969).
Illinois:
Richard D Irwin.
Gaya Chicago
Economics.
Ed.3, Cet.10.
Illinois:
Richard D Irwin,
1969.
.
Gaya MLA
Economics.
Ed.3, Cet.10.
Illinois:
Richard D Irwin,
1969.
.
Gaya Turabian
Economics.
Illinois:
Richard D Irwin,
1969.
.