1. Population exposure to X-rays in U.S. 1964. PHS Pub No. 1519;Gitlin,1966
2. X-ray protection. NBS Handbook 15;National Committee on Radiation Protection and Measurements US Department of Commerce,1931
3. X-ray protection. NBS Handbook 20;National Committee on Radiation Protection and Measurements US Department of Commerce,1936
4. Medical X-ray protection up to two million volts. NBS Handbook 41;National Committee on Radiation Protection and Measurements US Department of Commerce,1949