Included is a copy of the backside of the same Shunk-Kender photo which has the Shunk-Kender stamp on its backside for verification of authorship.

Shunk-Kender piece per John Gibson Gallery label on backside: Untitled, 1961, wood, steel & stainless,24 x 32 x 20 inches. NOTE: crease running across center of photo.
Other photo per written information on backside: wood, steel, 1961, 25 x 31 x 21.

Mark di Suvero is an internationally renowned sculptor who was born in Shanghai, China and immigrated to the United States in 1941 where he went on to receive a BA in Philosophy from the University of California, Berkeley.  One of the most important American artists to emerge from the Abstract Expressionist era, Di Suvero is recognized for his steel architectural-scale sculptures which often have moving elements that invite viewer participation.

The photographic duo of Harry Shunk (1924–2006) and János Kender (1938–2009), are recognized for producing some of the most iconic images of European and American art of the postwar era. From the late 1950s to the mid-1970s, a time of intense, rapid shifts in the perception of what constitutes an art object, the pair documented artists and exhibitions that were pivotal to the artistic developments of the time, including nouveau réalisme, pop art, minimalism, postminimalism, conceptual art, and performance.