Bibliography

Frederick Sommer: Selected Texts and Bibliography
Sheryl Conkelton, ed., and essay
(Oxford: Clio Press, 1995)

Words / Images
Frederick Sommer
(Center for Creative Photography, University of Arizona, 1984)
  Includes reprinted text from:
 The Poetic Logic of Art and Aesthetics
  (Stockton, NJ, Carolingian Press, 1972)
This two-volume set is still available at CCP and the easiest publication to delve into Sommer’s ideas through his own words. The CCP Museum store also has copies of the ‘Poetic Logic’ and the link to both is…Center for Creative Photography

Frederick Sommer at Seventy-Five, A Retrospective
Constance W. Glenn and Jane K. Bledsoe, eds.,
Introduction by Leland Rice
Essay by Jan-Gunnar Sjölin (translation by Ada M Fung).
(Long Beach: The Art Museum and Galleries, CSU, 1980)
  The Serpentine Gallery, London, during their exhibition published a variation of this catalog called Frederick Sommer: Photographs, Drawings and Musical Scores (1981) .
 
Venus, Jupiter and Mars:
The Photographs of Frederick Sommer
John Weiss, ed., and essay
Barbara Wendel, Charles Metzger and Ed Mitchell, chronology
(Wilmington: Delaware Art Museum, 1980)

Frederick Sommer
Gerald Nordland, ed., and essay
(Philadelphia: Philadelphia College of Art, 1968)

Harder to find but well worth it:

"Emmet Gowin on Frederick Sommer" contained within the Books on Photography III (1999) sales catalog by Roth Horowitz booksellers.

"Death Imagery in the Work of Four Twentieth-Century Artists:
Kathe Kollwitz, Mauricio Lasansky, Frederick Sommer and Jerome Liebling"
by Susan Von Glahn (now Susan Calabria)
Master of Fine Arts thesis paper
(University of New Mexico, Albuquerque, 1985)
[Katie Kollwitz is correctly spelled Kathë, but it can often be missed in search results with that spelling]

"Frederick Sommer: Photographic and Philosophical Development"
Mary Ann Fittipaldi
Master of Arts thesis paper
(East Texas State University, 1981)

Creative Camera No. 204
Articles by Mark Haworth-Booth and Dawn Ades
(December 1981)

Philadelphia Photo Review
Vol. 5 No. 1 Spring / Summer 1980
Article by Stephen Perloff

Linguistic & Pictorial Logic of General Aesthetics:
A Discussion of the Ornamental Sense of Ideas
(A transcription of the Princeton seminars,
 taught by Frederick Sommer in 1979)

Frederick Sommer interviewed by James McQuaid for the George Eastman House Oral History Project (December 2-6, 1976). An unpublished interview with Sommer, conducted as part of the NEH funded George Eastman House Oral History Project.
  Copies of this interview are located at The Richard and Ronay Menschel Library, George Eastman House, International Museum of Photography and Film; Center for Creative Photography, University of Arizona, Tucson; and the Frederick & Frances Sommer Foundation, Prescott, Arizona.

Audio-tape and transcription (by Richard Nickel) of the 1963 interview between Studs Terkel and Frederick Sommer – a copy is located at CCP though considerations regarding copyright with Studs Terkel have not yet been clarified.

Aperture 10:4 1962 -  Sommer’s first monograph, occasionally referred to as, Frederick Sommer 1939-1962 and noted in both: The Open Book: A History of the Photographic Book from 1878 to Present (Goteborg, Sweden: Hasselblad Center, 2004)
and The Book of 101 Books: Seminal Photographic Books of the 20th Century (New York: Horowitz, 2001).

As of December 2005 the Frederick & Frances Sommer Foundation has compiled a list of over 330 newspaper, magazine and book citations that in some way refer to Frederick Sommer.