Home › Authors › Underground Coal Conversion Symposium (5th 1979 Alexandria, Va.) 👤 Underground Coal Conversion Symposium (5th 1979 Alexandria, Va.) 1 book Books by Underground Coal Conversion Symposium (5th 1979 Alexandria, Va.) Proceedings of the 5th undergr Proceedings of the 5th underground coal conversion symposium, Alexandria, Virginia, June 18-21, 1979 1979