1. Letter from Harold Varmus to Mike Fried, Imperial Cancer Research Fund Laboratories Publication: Produced: 11 July 1977 Subject(s): Mammary Tumor Virus, MouseAvian Sarcoma VirusesRNA, ViralClone Cells Archival Collection: The Harold Varmus Papers (Profiles in Science)
2. Letter from Harold Varmus to Roel Nusse Publication: Produced: [28 March 1979] Subject(s): Mammary Tumor Virus, MouseDNA, ViralRNA, Viral Archival Collection: The Harold Varmus Papers (Profiles in Science)