1. Letter from Lewis Hackett to Fred L. Soper Publication: Produced: 9 March 1958 Subject(s): Lice InfestationsInsect Control Archival Collection: The Fred L. Soper Papers (Profiles in Science)
2. Letter from Lewis Hackett to Fred L. Soper Publication: Produced: 12 January 1959 Subject(s): Insect ControlDDTYellow Fever Vaccine Archival Collection: The Fred L. Soper Papers (Profiles in Science)