21. Letter from I. D. Michelson to Joshua Lederberg Publication: Produced: 10 October 1949 Subject(s): Cell Culture Techniques Archival Collection: The Joshua Lederberg Papers (Profiles in Science)
22. Letter from Joshua Lederberg to M. Demerec Publication: Produced: 17 February 1949 Subject(s): BacteriophagesCell Culture TechniquesRecombination, Genetic Archival Collection: The Joshua Lederberg Papers (Profiles in Science)
23. Letter from Joshua Lederberg to Bernard D. Davis Publication: Produced: 31 October 1949 Subject(s): Cell Culture TechniquesGenetics, MicrobialTeaching Archival Collection: The Joshua Lederberg Papers (Profiles in Science)