For anyone researching the origins of a particular icon or developing a new signage system, the Symbol Sourcebook (PDF format) is often considered the definitive "Bible". Exploring the Symbol Sourcebook PDF: Structure and Content

Many academic institutions have digitized their design library archives. If you are a student or faculty member, check your institutional login for access to rare design monographs.

The Symbol Sourcebook is far more than a simple dictionary of symbols. Dreyfuss designed it with extraordinary care to be as practical and easy to use as possible, organizing its vast contents into four cleverly devised sections that allow users to find and identify symbols from multiple entry points.