On the Present Distribution and Origin of the Calcareous .
WEBDOI: / Corpus ID: ; On the Present Distribution and Origin of the Calcareous Concretions in Coal Seams, Known as "Coal Balls" article{StopesOnTP, title={On the Present Distribution and Origin of the Calcareous Concretions in Coal Seams, Known as "Coal Balls"}, author={Marie Charlotte .