APA (7th ed.) Citation

Ratzan, L. (2004). Understanding information systems: What they do and why we need them. American Library Association.

Chicago Style (17th ed.) Citation

Ratzan, Lee. Understanding Information Systems: What They Do and Why We Need Them. Chicago: American Library Association, 2004.

MLA (9th ed.) Citation

Ratzan, Lee. Understanding Information Systems: What They Do and Why We Need Them. American Library Association, 2004.