- Umbrella journal, ed. Judith Hoffberg, Santa Monica, CA: Umbrella Associates, 1978-2008, Log. The journal covered news and reviews of artists' books, mail art and contemporary art and photography tradebooks.
- Hoffberg at Mail Artists Index
- Anthony Marcus Leslie, The Career and Collection of Judith A. Hoffberg, University of California, 2012, 151 pp. Master's thesis.