Kentucky State Highway Department (January 1, 1928). Map of Kentucky Showing Condition of State Roads(PDF) (Map). Scale not given. Frankfort: Kentucky State Highway Department. Retrieved October 7, 2014.
Michigan Department of Transportation (April 28, 2004). "Chapter One"(PDF). US 41/M-28 Access Management Plan. Michigan Department of Transportation. Archived from the original(PDF) on December 23, 2007. Retrieved January 18, 2008.
Michigan Department of Transportation (April 23, 2006). National Highway System, Michigan(PDF) (Map). Scale not given. Lansing: Michigan Department of Transportation. Retrieved February 4, 2008.
Michigan Department of Transportation (April 28, 2004). "Chapter One"(PDF). US 41/M-28 Access Management Plan. Michigan Department of Transportation. Archived from the original(PDF) on December 23, 2007. Retrieved January 18, 2008.