21. Letter from Donald S. Fredrickson to Daniel E. Koshland, Jr Creator: Fredrickson, Donald S.National Institutes of Health (U.S.) Date: 23 August 1976 Genre: Letters (correspondence)
22. Letter from Howard Raiffa to Maxine Singer Creator: National Research Council (U.S.)Raiffa, Howard Date: 17 April 1980 Genre: Letters (correspondence)
23. Letter from James L. Sullivan, City Manager, City of Cambridge, Massachusetts to the Mayor and City Council Creator: The City of Cambridge, MassachusettsSullivan, James L. Date: 6 August 1976 Genre: Letters (correspondence)
24. Letter from Joshua Lederberg to U.S. Senators Alan Cranston and Samuel Ichiye Hayakawa Creator: Lederberg, Joshua Date: [ca. 9 June 1977] Genre: Letters (correspondence)
25. Letter from London Ganning to Maxine Singer Creator: Ganning, London Date: 24 July 1979 Genre: Letters (correspondence)
26. Letter from Maxine Singer to C. G. Bernhard Creator: Singer, Maxine Date: 5 July 1977 Genre: Letters (correspondence)
27. Letter from Maxine Singer to Carolyn E. Kemp Creator: Singer, Maxine Date: 27 November 1978 Genre: Letters (correspondence)
28. Letter from Maxine Singer to Charles Warren Creator: Singer, Maxine Date: 7 January 1977 Genre: Letters (correspondence)
29. Letter from Maxine Singer to Donald S. Fredrickson Creator: Singer, Maxine Date: 5 October 1977 Genre: Letters (correspondence)
30. Letter from Maxine Singer to Francesco Blasi Creator: Singer, Maxine Date: 3 March 1976 Genre: Letters (correspondence)