1. Letter from Felix Haurowitz to Michael Heidelberger Publication: Produced: 9 January 1943 Subject(s): World War IIComplement System Proteins Archival Collection: The Michael Heidelberger Papers (Profiles in Science)
2. Letter from Otto Bier, Instituto Biologico (Brazil) to Michael Heidelberger Publication: Produced: 11 September 1944 Subject(s): Complement System ProteinsWorld War II Archival Collection: The Michael Heidelberger Papers (Profiles in Science)