31. Letter from Elvin A. Kabat to Michael Heidelberger Publication: Produced: [22 July 1938] Subject(s): Immune SeraAntibodiesCrystallography, X-RayMolecular Weight Archival Collection: The Michael Heidelberger Papers (Profiles in Science)
32. Letter from Simon Flexner, Rockefeller Institute for Medical Research to Michael Heidelberger Publication: Produced: 23 June 1924 Subject(s): Crystallography, X-RayAllergy and Immunology Archival Collection: The Michael Heidelberger Papers (Profiles in Science)