@article {261, title = {The occurrence of Phytophthora cinnamomi in the soil under pine stands in the southeast.}, journal = {Phytopathology}, volume = {41}, year = {1951}, pages = {742-746}, author = {Campbell, W.A.} } @article {campbell1954littleleaf, title = {Littleleaf disease of shortleaf and loblolly pines}, number = {Circular no. 940.}, year = {1954}, pages = {41 pages}, publisher = {USDA Forest Service}, address = {Washington, DC}, author = {Campbell, W.A. and Copeland, O.L.} }