SCHOPF, James M.
Field description and sampling of coal beds / by James M. Schopf. -- Washington : United States Government Printing Office, 1960 - P. 25-70 p., [14] h. de lam. -- (Geological Survey Bulletin ; 1111-B).
Geología
55
Field description and sampling of coal beds / by James M. Schopf. -- Washington : United States Government Printing Office, 1960 - P. 25-70 p., [14] h. de lam. -- (Geological Survey Bulletin ; 1111-B).
Geología
55