Bates, John. Trailside Botany: 101 Favorite Trees, Shrubs, and Wildflowers of the Upper           Midwest. Duluth: Pfeifer-Hamilton, 1995.
Grimm, William Carey. The Illustrated Book of Trees: The Comprehensive Field Guide to           More Than 250 Trees of Eastern North America. Harrisburg: Stackpole Books,           1957.
Kalinowski, Tom. Adirondack Almanac: A Guide to the Natural Year. Utica: North           Country Books, 1999.
Levine, Carol. A Guide to Wildflowers in Winter. New Haven: Yale University Press,           1995.
Peterson, Roger Tory, and Margaret McKenny. A Field Guide to Wildflowers:           Northeastern and Northcentral North American. New York: Houghton Mifflin,           1968.
Smith, Norman F. Trees of Michigan and the Upper Great Lakes. Holt, MI: Thunder Bay           Press, 1952
Stokes, Donald. Stokes Guide to Nature in Winter: Northeast and North Central North           America. New York: Little, Brown and Company, 1976.