Boyd, M. and Surette, C.
  2010  Northernmost precontact maize in North America. American Antiquity 75: 117-133.

Boyd, M.,  Varney, T., Surette, C., and Surette, J.
  2008  Reassessing the northern limit of maize consumption in North America: Stable isotope, plant microfossil, and trace element content of carbonized food residue. Journal of Archaeological Science.
Boyd, M., Surette, C., and Nicholson, B.A. 
  2006  Archaeobotanical Evidence of Prehistoric Maize (Zea mays) Consumption at the Northern Edge of the Great Plains. Journal of Archaeological Science 33:1129-1140.