Map of Land-Grant Colleges and Universities(PDF). United States Department of Agriculture, Cooperative State Research, Education, and Extension Service. [2015-10-05]. (原始内容(PDF)存档于2009-10-08).
Map of Land-Grant Colleges and Universities(PDF). United States Department of Agriculture, Cooperative State Research, Education, and Extension Service. [2015-10-05]. (原始内容(PDF)存档于2009-10-08).