Research study--Isard, Langford, Jr.; "Philadelphia Region Input-Output Study Working Papers, Volume IV", Jul-68

Research study--Isard, Langford, Jr.; "Philadelphia Region Input-Output Study Working Papers, Volume IV", Jul-68, Box: 9, Folder: 2. Walter Isard papers, 3959. Division of Rare and Manuscript Collections. https://archives.library.cornell.edu/repositories/2/archival_objects/427850 Accessed January 02, 2026.