Cita APA (7th ed.)

Haag, S., & Cummings, M. (2008). Information systems essentials (2nd ed.). McGraw-Hill/Irwin.

Cita Chicago (17th ed.)

Haag, Stephen, i Maeve Cummings. Information Systems Essentials. 2nd ed. Boston: McGraw-Hill/Irwin, 2008.

Cita MLA (9th ed.)

Haag, Stephen, i Maeve Cummings. Information Systems Essentials. 2nd ed. McGraw-Hill/Irwin, 2008.