Economics;
principles and problems,
by Paul F. Gemmill and Ralph H. Blodgett.

APA Citation

Gemmill, P. Fleming., Blodgett, R. Hamilton. (1948). Economics: principles and problems. 3d ed. New York: Harper.

MLA Citation

Gemmill, Paul Fleming, 1889-, and Ralph Hamilton Blodgett. Economics: Principles And Problems. 3d ed. New York: Harper, 1948.

Warning: These citations may not always be complete (especially for serials).