TY - BOOK ID - 136134723 TI - Bibliography and index of U.S. Geological Survey publications relating to coal, 1971-1975 AU - Walker, Flora K. AU - Geological Survey (U.S.) PY - 1976 PB - [Reston, Virginia] : United States Department of the Interior, Geological Survey, DB - UniCat KW - Coal mines and mining KW - Coal KW - Coal mines and mining KW - Coal KW - United States. UR - https://www.unicat.be/uniCat?func=search&query=sysid:136134723 AB - ER -