Phytosociological analysis of Aspen communities on three site classis for populus Grandidentata in western Cheboygan County, Michigan. - Den Haag - Benninghoff, William S. (Vegetatio : Acta Geobotanica ; 11.1963, Fasc. 5-6, S. 253-264 : 1 Ill. ; 2 Kt. ; 3 Tab., 1963)