1. API (American Petroleum Institute Bulletin), 1992. Bulletin E2 on Management of Naturally Occurring Radioactive Materials (NORM) in Oil and Gas Production, Washington DC
2. On the isotopic constitution of radium (Ra224/Ra226 and Ra228/Ra226) in petroleum brines, EOS;Armbrust;Trans. Am. Geophys. Union,1956
3. Bradley, D.A., 1996. Land Disturbance and the Environmental Pollution From Oil-and Gas-Well Drilling and Extraction, with Special Reference to Naturally Occurring Radioactive Materials. UNESCO – EOLSS (Encyclopedia of Life Support Systems): Interactions: Energy/Environment. 〈http://www.eolss.net/outlinecomponents/Interactions-Energy-Environment.aspx〉
4. Naturally occurring radioactive material in the environment;Bradley;Appl. Radiat. Isot.,1998
5. 232Th-228Ra-228Th disequilibrium in East China Sea sediments;Chen;J. Environ. Radioact.,1999