[CL001106], Agreement, National Phonograph Co, Seeley Tube and Box Co, May 1st, 1908
[CL001-F] Company Records Series -- National Phonograph Company
https://edisondigital.rutgers.edu/document/CL001106
Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University
Archive.org Viewer, Microfilm Series Reel 156