1. Boundary Waters Canoe Area Land Use Plan 1974
2. Bradbury, J. P., Quaternary Plant Ecology: 289 (1973).
3. Proceedings of the 19th Congress of the International Association of Limnology 1974
4. DECIDUOUS FORESTS EA 1950
5. BRAUN, E.L., OHIO JOURNAL OF SCIENCE 51: 1939 (1951).