Gore, M. R., & Stubbe, J. (1979). Elements of systems analysis for business data processing (2d ed.). W. C. Brown Co..

Gore, Marvin R., and John Stubbe. Elements of Systems Analysis for Business Data Processing. 2d ed. Dubuque, Iowa: W. C. Brown Co., 1979.

Gore, Marvin R., and John Stubbe. Elements of Systems Analysis for Business Data Processing. 2d ed. W. C. Brown Co., 1979.