^Executive Committee (November 16, 1930). "Minutes of Executive Committee"(PDF) (Report). Washington, DC: American Association of State Highway Officials. Retrieved June 25, 2022 – via Wikimedia Commons.
^Illinois Secretary of State (1932). Official Illinois Highway Map (Map). [c. 1:950,000 and c. 1:1,110,000]. Springfield: Illinois Division of Highways. Retrieved June 25, 2022 – via Illinois Digital Archives.
^Illinois Secretary of State; Rand McNally (1934). Official Road Map Illinois (Map). [c. 1:950,000 and c. 1:1,110,000]. Springfield: Illinois Secretary of State. OCLC183709045. Retrieved June 25, 2022 – via Illinois Digital Archives.
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