Interstate 72 (English Wikipedia)

Johnston, Louis; Williamson, Samuel H. (2023). "What Was the U.S. GDP Then?". MeasuringWorth. Retrieved November 30, 2023. United States Gross Domestic Product deflator figures follow the MeasuringWorth series.

missourinet.com (Global: low place; English: low place)

Morabith, Anthony (June 8, 2023). "Chillicothe Senator skeptical about possibly converting U.S. Highway 36 into Interstate 72". Missourinet. Retrieved June 27, 2023.
Griffin, Marshall (July 31, 2023). "Gov. Parson explains why he vetoed an I-72 study". Missourinet. Retrieved August 21, 2023.

Missouri Department of Transportation (November 13, 2012). MoDOT HPMAPS (Map). Missouri Department of Transportation. Retrieved November 13, 2012.

Erickson, Kurt (May 23, 2023). "Missouri could be poised to gain another interstate highway". STLtoday.com. Retrieved June 27, 2023.

American Association of State Highway and Transportation Officials (June 9, 1991). "Report of the Special Committee on U.S. Route Numbering to the Executive Committee" (PDF). Archived from the original (PDF) on October 13, 2006. Retrieved December 19, 2007.
American Association of State Highway and Transportation Officials (April 23, 1995). "Report of the Special Committee on U.S. Route Numbering to the Standing Committee on Highways" (PDF). Archived from the original (PDF) on February 4, 2007. Retrieved December 19, 2007.

American Association of State Highway and Transportation Officials (June 9, 1991). "Report of the Special Committee on U.S. Route Numbering to the Executive Committee" (PDF). Archived from the original (PDF) on October 13, 2006. Retrieved December 19, 2007.
American Association of State Highway and Transportation Officials (April 23, 1995). "Report of the Special Committee on U.S. Route Numbering to the Standing Committee on Highways" (PDF). Archived from the original (PDF) on February 4, 2007. Retrieved December 19, 2007.