1. Standard method for microscopical determination of the reflectance of the organic components in a polished specimen of coal;Annual Book of American Society for Testing and Materials;Gaseous fuels. Coal and Coke,1983
2. The configuration of the Pennsylvanian and Dunkard (Permian) strata in West Virginia; a challenge to classical concepts;Arkle,1969
3. Field geologist's manual;Berkman;Aust. Inst. Min. Metall., Monogr.,1976
4. Coal-bearing Upper Pennsylvanian and Lower Permian rocks, Washington area, Pennsylvania;Berryhill;U.S. Geol. Surv., Prof. Pap. 621,1971
5. Heat from radioactivity;Birch,1954