Gaya APA
Umbreit, M, H. et al (1948).
Fundamentals of Economics .
London:
McGraw-Hill Book Company, Inc. - New York.
Gaya MLA
Umbreit, Myron, H.. et al.
"Fundamentals of Economics".
London:
McGraw-Hill Book Company, Inc. - New York,
1948.
Koleksi Elektronik.