501. Letter from Paul Berg, Stanford University Medical Center to Marshall W. Nirenberg Publication: Produced: 15 April 1969 Archival Collection: The Marshall W. Nirenberg Papers (Profiles in Science)
502. Letter from Robert F. Murray Jr. to Marshall W. Nirenberg Publication: Produced: 28 October 1969 Archival Collection: The Marshall W. Nirenberg Papers (Profiles in Science)