Gaya APA
Salvatore, D., Diulio, E, A. (1983).
Theory and problems of principles of economics .
Singapore:
McGraw-Hill.
Gaya MLA
Salvatore, Dominick., Diulio, Eugene, A..
"Theory and problems of principles of economics".
Singapore:
McGraw-Hill,
1983.
Buku/Printed Material.