Ratzan, L. (2004). Understanding information systems: What they do and why we need them. American Library Association.
Chicago-referens (17:e uppl.)Ratzan, Lee. Understanding Information Systems: What They Do and Why We Need Them. Chicago: American Library Association, 2004.
MLA-referens (9:e uppl.)Ratzan, Lee. Understanding Information Systems: What They Do and Why We Need Them. American Library Association, 2004.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.