found: Clegg & Guttmann, collected portraits, c1988:t.p. (Clegg & Guttmann) p. 29 (apparently a photographic studio in New York; Michael Clegg and Martin Guttmann)
found: Clegg & Guttmann, corporate landscapes, 1989:t.p. (Clegg & Guttmann) p. 5, etc. (Michael Clegg and Martin Guttmann, photographers; b. 1957; live and work in New York)
found: Monument for historical change and other social sculptures, community portraits and spontaneous operas, 1990-2005, c2005:t.p. (Clegg & Guttmann)
found: Grove art online, June 29, 2006(Clegg & Guttman; American photographers and conceptual artists of Irish and Israeli birth; Michael Clegg, b. Dublin, 1957; Martin Guttman, b. Jerusalem, 1957)
found: Union list of artist names, June 29, 2006(individual entries for Clegg, Michael (American photographer, born 1957) and Guttman, Martin (American photographer, born 1957); no collective entry for Clegg & Guttman though individual entries mention collaboration)