Connecticut Agricultural Experiment Station. Plant Disease Information Office.
University of Connecticut. Department of Plant Science and Landscape Architecture.
University of Connecticut. Connecticut Invasive Plant Working Group.
Maine Department of Conservation. Maine Forest Service. Forest Health and Monitoring Division.
University of Maine. Cooperative Extension.
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.
Vermont Agency of Natural Resources. Department of Environmental Conservation.