TY  - RPRT
TI  - The valuation of public coal lands: The value of coal land; Depth and minimum thickness of beds as limiting factors in valuation
AU  - George H. Ashley
AU  - Cassius Fisher
PY  - 1910
DO  - 10.3133/b424
UR  - https://pubs.usgs.gov/publication/b424
ID  - b424
ER  -