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Minnesota Legislature. "§161.115 Additional Trunk Highways". Minnesota Statutes. Minnesota Office of the Revisor of Statutes. Archived from the original on March 7, 2007. Retrieved January 7, 2007.
Minnesota Legislature. "§161.114 Constitutional Trunk Highways". Minnesota Statutes. Minnesota Office of the Revisor of Statutes. Archived from the original on May 9, 2007. Retrieved January 7, 2007.
Bessert, Christopher J. (July 5, 2013). "US-12". Michigan Highways. Archived from the original on December 19, 2013. Retrieved January 19, 2014.[self-published source]
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