Spengler, E. H. 1., & Klein, J. 1. (1955). Introduction to business. McGraw-Hill.
Cita Chicago (17th ed.)Spengler, Edwin Harold 1906, i Jacob 1896 Klein. Introduction to Business. New York: McGraw-Hill, 1955.
Cita MLA (9th ed.)Spengler, Edwin Harold 1906, i Jacob 1896 Klein. Introduction to Business. McGraw-Hill, 1955.
Atenció: Aquestes cites poden no estar 100% correctes.