1. Letter from Paul Berg to Donald S. Fredrickson Publication: Produced: 20 August 1979 Subject(s): DNA, RecombinantEscherichia coli Archival Collection: The Paul Berg Papers (Profiles in Science)
2. Letter from Paul Berg to Donald S. Fredrickson Publication: Produced: 17 December 1979 Subject(s): DNA, RecombinantEscherichia coli Archival Collection: The Paul Berg Papers (Profiles in Science)