Spencer, M. A. (1987). Coal resources of the Twomile Creek and portions of adjacent Frog Coulee 7 1/2-minute quadrangles, Richland County, Montana. Montana Bureau of Mines and Geology.
Chicago Style (17th ed.) CitationSpencer, Mary Alice. Coal Resources of the Twomile Creek and Portions of Adjacent Frog Coulee 7 1/2-minute Quadrangles, Richland County, Montana. [Butte]: Montana Bureau of Mines and Geology, 1987.
MLA (9th ed.) CitationSpencer, Mary Alice. Coal Resources of the Twomile Creek and Portions of Adjacent Frog Coulee 7 1/2-minute Quadrangles, Richland County, Montana. Montana Bureau of Mines and Geology, 1987.
Warning: These citations may not always be 100% accurate.