Vegetation and Tree Species Patterns near the Northern Terminus of the Southern Floodplain ForestPhilip A. Robertson, James A. Cavanaugh, George T. Weaver|Ecological Monographs|1978Cited by 166
Sugar Maple Invasion of an Old-growth Oak-hickory Forest in Southwestern IllinoisSteven J. Shotola, W. C. Ashby, Philip A. Robertson et al.|The American Midland Naturalist|1992Cited by 92
Regrowth of Quercus prinus and Associated Tree Species Following Regeneration Harvesting in the Ozark Hills of IllinoisGeorge T. Weaver, Philip A. Robertson|Bulletin of the Torrey Botanical Club|1981Cited by 11