Connecticut Agricultural Experiment Station. Plant Disease Information Office.
University of Connecticut. Department of Plant Science and Landscape Architecture.
Virginia Department of Forestry.
University of Connecticut. Connecticut Invasive Plant Working Group.
University of New Hampshire. Cooperative Extension; New Hampshire Department of Agriculture, Markets & Food.
Utah Department of Agriculture and Food.
University of New Hampshire. Cooperative Extension.
Virginia Department of Conservation and Recreation.
Vermont Agency of Natural Resources. Department of Environmental Conservation.