Delaware Department of Transportation (2017). Official Travel & Transportation Map(PDF) (Map). Dover: Delaware Department of Transportation. Retrieved August 18, 2019.
Report of the State Highway Department(PDF) (1950 ed.). Dover, Delaware: Delaware State Highway Department. July 1, 1950. pp. 27–29. Archived from the original(PDF) on September 23, 2015. Retrieved November 9, 2014.
Report of the State Highway Department(PDF) (1951 ed.). Dover, Delaware: Delaware State Highway Department. July 1, 1951. p. 41. Archived from the original(PDF) on September 23, 2015. Retrieved November 9, 2014.
Report of the State Highway Department(PDF) (1954 ed.). Dover, Delaware: Delaware State Highway Department. July 1, 1954. p. 84. Archived from the original(PDF) on September 23, 2015. Retrieved November 9, 2014.
Report of the State Highway Department(PDF) (1956 ed.). Dover, Delaware: Delaware State Highway Department. July 1, 1956. pp. 8, 21. Archived from the original(PDF) on January 7, 2010. Retrieved November 9, 2014.
Annual Report(PDF) (1964 ed.). Dover, Delaware: Delaware State Highway Department. 1964. p. 20. Archived from the original(PDF) on September 23, 2015. Retrieved November 10, 2014.
Annual Report(PDF) (1965 ed.). Dover, Delaware: Delaware State Highway Department. 1965. p. 33. Retrieved November 11, 2014.
Annual Report(PDF) (1966 ed.). Dover, Delaware: Delaware State Highway Department. 1966. p. 12. Retrieved November 11, 2014.
Annual Report(PDF) (1968 ed.). Dover, Delaware: Delaware State Highway Department. June 30, 1968. p. 20. Retrieved November 11, 2014.
Annual Report(PDF) (1969 ed.). Dover, Delaware: Delaware State Highway Department. June 30, 1969. p. 8. Retrieved November 11, 2014.
Delaware Department of Transportation (1985). Official State Highway Map(PDF) (Map). Dover: Delaware Department of Transportation. Retrieved November 24, 2015.
"State Route 1 Project Timeline". Internet Archives WayBack Machine. Delaware Department of Transportation. Archived from the original on June 24, 2003. Retrieved October 16, 2014.
Report of the State Highway Department(PDF) (1950 ed.). Dover, Delaware: Delaware State Highway Department. July 1, 1950. pp. 27–29. Archived from the original(PDF) on September 23, 2015. Retrieved November 9, 2014.
Report of the State Highway Department(PDF) (1951 ed.). Dover, Delaware: Delaware State Highway Department. July 1, 1951. p. 41. Archived from the original(PDF) on September 23, 2015. Retrieved November 9, 2014.
Report of the State Highway Department(PDF) (1954 ed.). Dover, Delaware: Delaware State Highway Department. July 1, 1954. p. 84. Archived from the original(PDF) on September 23, 2015. Retrieved November 9, 2014.
Report of the State Highway Department(PDF) (1956 ed.). Dover, Delaware: Delaware State Highway Department. July 1, 1956. pp. 8, 21. Archived from the original(PDF) on January 7, 2010. Retrieved November 9, 2014.
Annual Report(PDF) (1964 ed.). Dover, Delaware: Delaware State Highway Department. 1964. p. 20. Archived from the original(PDF) on September 23, 2015. Retrieved November 10, 2014.
"State Route 1 Project Timeline". Internet Archives WayBack Machine. Delaware Department of Transportation. Archived from the original on June 24, 2003. Retrieved October 16, 2014.
Special Committee on U.S. Route Numbering (November 14, 1980). "Route Numbering Committee Agenda"(PDF) (Report). Washington, DC: American Association of State Highway and Transportation Officials. p. 519. Retrieved November 13, 2014 – via Wikimedia Commons.
Special Committee on U.S. Route Numbering (December 7, 1984). "Route Numbering Committee Agenda"(PDF) (Report). Washington, DC: American Association of State Highway and Transportation Officials. p. 546. Retrieved October 15, 2014 – via Wikimedia Commons.