8. Advanced Planning Division, New Castle County Department of Planning. Population: A County Comprehensive Development Plan Background Study New Castle County, Delaware. Wilmington, Del.: Advanced Planning Division, New Castle County Department of Planning, 1966. S9.3/No. 7/Vol. 1

8. Advanced Planning Division, New Castle County Department of Planning. Population: A County Comprehensive Development Plan Background Study New Castle County, Delaware. Wilmington, Del.: Advanced Planning Division, New Castle County Department of Planning, 1966. S9.3/No. 7/Vol. 1, Box: 20. William J. Cohen papers, MSS 0468. University of Delaware Library Special Collections. https://findingaids.lib.udel.edu/repositories/2/archival_objects/191342 Accessed September 18, 2024.