1. American Society for Testing and Materials Standard test methods for total and dissolved carbon dioxide in water 1992
2. American Society for Testing and Materials Standard test methods for instrumental determination of carbon, hydrogen, and nitrogen in laboratory samples of coal and coke 1993
3. American Society for Testing and Materials Standard test methods for sulfur in the analysis sample of coal and coke using high temperature tube furnace combustion methods 1994
4. Nitrogen-isotope compositions of metasedimentary rocks in the Catalina Schist, California: Implications for metamorphic devolatilization history;Bebout;Geochim. Cosmochim. Acta,1992
5. Bjorklund , L. J. R. F. Brown Geology and ground-water resources of the Lower South Platte River valley between Hardin, Colorado and Paxton, Nebraska, U.S. Geol. Surv. Water Supply Pap. 1378 1957