1. Letter from Harold Varmus to Ed Southern, Medical Research Council of Great Britain Publication: Produced: 4 November 1977 Subject(s): Avian Sarcoma VirusesDNA, ViralSarcoma Viruses, MurineCloning, Molecular Archival Collection: The Harold Varmus Papers (Profiles in Science)
2. Letter from Harold Varmus to Mike Fried, Imperial Cancer Research Fund Laboratories Publication: Produced: [8 February 1978] Subject(s): DNA, ViralAvian Sarcoma VirusesCloning, MolecularRNA, Viral Archival Collection: The Harold Varmus Papers (Profiles in Science)