Gaya APA
Roy Ruffin, Sr. (1983).
Principles of Economics .
:
Scott, Foresman and Company.
Gaya Chicago
Roy Ruffin, Sr.
Principles of Economics.
:
Scott, Foresman and Company,
1983.
Text.
Gaya MLA
Roy Ruffin, Sr.
Principles of Economics.
:
Scott, Foresman and Company,
1983.
Text.
Gaya Turabian
Roy Ruffin, Sr.
Principles of Economics.
:
Scott, Foresman and Company,
1983.
Print.