found: The Architectural photography of Hedrich-Blessing, c1982 (a.e.)CIP t.p. (Hedrich-Blessing) text (Chicago-based enterprise, architectural photography)
found: Pridmore, Jay. The Reliance Building, 2003:CIP t.p. (HedrichBlessing)
found: CaQMCCA files, Oct. 29, 2002(firm was formed by three Hedrich brothers, Ken, Ed, and Bill, who joined in 1931 with associate Henri Blessing)
found: Chicago architecture and design, 2018:Back cover inside flap (Hedrich Blessing, which closed in 2017 was one of the country's premier architectural photography studios, and since 1929 was associated with Chicago's leading architects. Its successor firm of Hall + Merrick Photographers is based in Chicago)
