Gaya APA
Ruffin, R, J., Gregory, P, R. (1985).
Principles of macroeconomics ed.2 .
Cincinnati:
Scott; Foresman and company.
Gaya MLA
Ruffin, Roy, J., Gregory, Paul, R.
"Principles of macroeconomics ed.2".
Cincinnati:
Scott; Foresman and company,
1985.
Text.