In a large project such as this, many photos are needed to produce a professional product. The authors utilized photographs from the USDA-Agricultural Research Service, the USDA-Natural Resources Conservation Service, International Maize and Wheat Improvement Center (CIMMYT), Iowa State University Extension, D.G. Mackean, the Doebley Lab (University of Wisconsin-Madison), the John Deere Company, David L. Hansen (Agricultural Experiment Station, U of MN), U of MN Extension, Strand Memorial Herbarium, Carmen Fernholz (U of MN), Lizabeth Stahl (U of MN), Bill Hutchinson (U of MN), and others. We would like to thank all the photographers for the use of their materials.
We used royalty-free music by Kevin MacLeod for our modules. These pieces can be found at: http://incompetech.com/music/royalty-free/.