1967. This georeferenced raster layer represents locations of energy sources in China in 1967. It is taken from the book, Communist China: Map Folio, whi... Directorate of Intelligence, Office of Basic and Geographic Intelligence.
2001. Eastern Energy Resource Surveys Team (Geological Survey). This polygon shapefile shows the coal fields of Alaska and the conterminous United States. Most of the material for the conterminous United States ... National Atlas of the United States.