http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Proceedings of the third International conference on bituminous coal
International Conference on Bituminous Coal 1931 : Pittsburgh)
2 volumes : illustrations, tables (1 folded) diagrams ; 24 cm.
November 16 to 21, 1931, Carnegie Institute of Technology, Pittsburgh, Pennsylvania.