Differential (US Patent 2,775142)
name: label: Collection Creator
content: Page Tractor Company
setName: label: See more items in
content: Page Tractor Company Papers
unitdate: label: Date
content: 1956
container: label: Container
content: Box 2, Folder 11
dataSource: label: Archival Repository
content: Archives Center, National Museum of American History
objectType: label: Type
content: Archival materials