SRF Consulting Group, Inc. (July 2010). "NLX Open House Boards"(PDF). Northern Lights Express. Archived from the original(PDF) on July 27, 2011. Retrieved September 22, 2010.
"Meeting Minutes"(PDF). Minnesota Department of Transportation. April 6, 2009. Archived from the original(PDF) on September 2, 2012. Retrieved December 21, 2009.
Minneapolis–Duluth/Superior: Restoration of Intercity Passenger Rail Service Comprehensive Feasibility Study and Business Plan (ch. 1–2, ch 3, ch 4–10, appendices). Transportation Economics & Management Systems, Inc., December 2007. Accessed December 18, 2009.
SRF Consulting Group, Inc. (July 2010). "NLX Open House Boards"(PDF). Northern Lights Express. Archived from the original(PDF) on July 27, 2011. Retrieved September 22, 2010.
"Meeting Minutes"(PDF). Minnesota Department of Transportation. April 6, 2009. Archived from the original(PDF) on September 2, 2012. Retrieved December 21, 2009.