1. Letter from Harold Varmus to Don Robertson, Washington University Publication: Produced: 1 April 1976 Subject(s): Mammary Tumor Virus, MouseDNA, Viral 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)