http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Resources in sedimentary rocks of the Powder River Basin and adjacent uplifts, northeastern Wyoming
by Ray E. Harris, Rodney H. DeBruin, and Richard W. Jones.
Evolution of sedimentary basins--Powder River Basin ; ch. N