Ratzan, L. (2004). Understanding information systems: What they do and why we need them. American Library Association.
Chicago-viite (17. p.)Ratzan, Lee. Understanding Information Systems: What They Do and Why We Need Them. Chicago: American Library Association, 2004.
MLA-viite (9. p.)Ratzan, Lee. Understanding Information Systems: What They Do and Why We Need Them. American Library Association, 2004.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.