TY  - SER
ED  - Estados Unidos.
TI  - Technical Paper
PY  - 1915///-
CY  - Washington DC
PB  - Bureau of Mines
KW  - Metodología
KW  - Minería
N1  - no.576(1937) Bibliography of United States. Bureau of Mines Investigation on coal and its products 1910-35
ER  -