Analysis: Irving Penn's Platinum Prints
An article by David Travis titled "Platinum Prints by Irving Penn" describing the artist's platinum printing process on the occasion of the 1977 gift to the Art Institute of Chicago of ten platinum prints by Mrs. Leigh B. Block.

Bulletin of the Art Institute of Chicago
The Art Institute of Chicago, Bulletin of the Art Institute of Chicago (1973-1983), 72, 4, p. 20.