Titles
- Letter from A. Lima-de-Faria to Joshua Lederberg2
- Letter from A. M. James to Joshua Lederberg1
- Letter from A. M. Pappenheimer, Jr. to Alden H. Emery, American Chemical Society1
- Letter from A. M. Pappenheimer, Jr. to Joshua Lederberg3
- Letter from A. M. Pappenheimer, Jr., University of Pennsylvania School of Medicine to Michael Heidelberger1
- Letter from A. M. Stewart to John W. Gofman1
- Letter from A. R. Gopal-Ayengar to Joshua Lederberg6
- Letter from A. R. Gopal-Ayengar to Joshua and Esther Lederberg1
- Letter from A. T. Ganesan to Joshua Lederberg4
- Letter from A. T. Ganesan to Joshua and Esther Lederberg7
- Letter from A. T. McCormack to Thomas Parran1
- Letter from A. T. Wilson to Joshua Lederberg2
- Letter from A. V. Hill to Francis Crick1
- Letter from A. W. Peterson to Warren Weaver, Rockefeller Foundation1
- Letter from Aaron Cohodes, Instructional Dynamics Incorporated to Joshua Lederberg2
- Letter from Aaron J. Shatkin to Daniel Nathans1
- Letter from Aaron J. Shatkin to Joshua Lederberg1
- Letter from Aaron J. Teller to Joshua Lederberg1
- Letter from Aaron Klug to F. C. Bawden1
- Letter from Aaron Klug to Francis Crick16