77. Delaware State Highway Department. Controlled Access Highways. Dover, Del.: Delaware State Highway Department, 1959. T1.5/No. 1

77. Delaware State Highway Department. Controlled Access Highways. Dover, Del.: Delaware State Highway Department, 1959. T1.5/No. 1, Box: 23. William J. Cohen papers, MSS 0468. University of Delaware Library Special Collections. https://findingaids.lib.udel.edu/repositories/2/archival_objects/191645 Accessed September 19, 2024.