Nickels, W. G., McHugh, J. M., & McHugh, S. M. (1993). Understanding business (3rd edition.). Irwin.

Nickels, William G., James M. McHugh, and Susan M. McHugh. Understanding Business. 3rd edition. Homewood, IL: Irwin, 1993.

Nickels, William G., et al. Understanding Business. 3rd edition. Irwin, 1993.