Forest Service History, General:
Forest History Society (FHS)
Society of American Foresters (SAF)
Grey Towers National Historic Site
Pinchot Institute for Conservation
Aldo Leopold Foundation
National Agricultural Library
Marsh Billings Rockefeller National Historic Park
National Park Service History
Yale School of Forestry and Environmental Studies
Denver Public Library
Smithsonian
The Greatest Good Teacher Guide
William R. Kreutzer, first official U.S. Forest Ranger