41. Letter from P. R. Edwards to Joshua Lederberg Creator: Edwards, Philip R. Date: 28 January 1955 Genre: Letters (correspondence)
42. Letter from P. R. Edwards to Joshua Lederberg Creator: Edwards, Philip R. Date: 22 March 1955 Genre: Letters (correspondence)
43. Letter from P. R. Edwards to Joshua Lederberg Creator: Edwards, Philip R. Date: 2 May 1955 Genre: Letters (correspondence)
44. Letter from P. R. Edwards to Joshua Lederberg Creator: Edwards, Philip R. Date: 18 April 1956 Genre: Letters (correspondence)
45. Letter from P. R. Edwards to Joshua Lederberg Creator: Edwards, Philip R. Date: 21 June 1956 Genre: Letters (correspondence)
46. Letter from P. R. Edwards to Joshua Lederberg Creator: Edwards, Philip R. Date: 25 April 1956 Genre: Letters (correspondence)
47. Letter from P. R. Edwards to Joshua Lederberg Creator: Edwards, Philip R. Date: 26 June 1962 Genre: Letters (correspondence)
48. Letter from P. R. Edwards to Joshua Lederberg Creator: Edwards, Philip R.United States. Public Health Service. Federal Security Agency Date: 1 October 1952 Genre: Letters (correspondence)
49. Letter from P. R. Edwards to Joshua Lederberg Creator: Edwards, Philip R.United States. Public Health Service. Federal Security Agency Date: 19 May 1952 Genre: Letters (correspondence)
50. Letter from P. R. Edwards to Joshua Lederberg Creator: Edwards, Philip R. Date: 25 November 1952 Genre: Letters (correspondence)