TY  - BOOK
AU  - Stopes M C
AU  - Watson D M S
TI  - On the present distribution and origin of the calcareous concretions in coal seams, known as coal balls
U1  - 553.2 
PY  - 1908///
CY  - London
PB  - Royal Soc.
KW  - Economic geology
KW  - Ore deposits
N1  - Philosophical Trans. of Royal Soc. of London, ser B, v 200, 1908
ER  -