1. Letter from Maxine Singer to Leon A. Heppel Creator: Singer, Maxine Date: 21 October 1955 Genre: Letters (correspondence)
2. Letter from Leon A. Heppel to Maxine Singer Creator: Heppel, Leon A.National Institutes of Health (U.S.) Date: 27 October 1955 Genre: Letters (correspondence)
3. Letter from Leon A. Heppel to Maxine Singer Creator: Heppel, Leon A.National Institutes of Health (U.S.) Date: 13 December 1955 Genre: Letters (correspondence)
4. Letter from Severo Ochoa to Maxine Singer Creator: Ochoa, Severo, 1905-1993New York University. College of Medicine Date: 11 November 1957 Genre: Letters (correspondence)
5. Letter from Leon A. Heppel to Maxine Singer Creator: Heppel, Leon A.National Institutes of Health (U.S.) Date: [28 December 1957?] Genre: Letters (correspondence)
6. Phosphorolysis of Oligoribonucleotides by Polynucleotide Phosphorylase Creator: Singer, Maxine Date: [1958] Publisher: American Society for Biochemistry and Molecular Biology Genre: Articles
7. Excerpt from Volume 6 of Singer's lab notebooks Creator: Singer, MaxineHilmoe, Russell Date: [27 March-5 June 1958] Genre: Laboratory notebooksExcerpts
8. Letter from Severo Ochoa to Maxine Singer Creator: Ochoa, Severo, 1905-1993New York University. College of Medicine Date: 24 May 1958 Genre: Letters (correspondence)
9. Letter from Maxine Singer to Severo Ochoa Creator: Singer, Maxine Date: 13 July 1958 Genre: Letters (correspondence)
10. Letter from Leon A. Heppel to Maxine Singer Creator: Heppel, Leon A. Date: [14 July 1958] Genre: Letters (correspondence)