1. DANIEL B. HOWELL. Personal communication. Isotopes Branch, Division of Materials Licensing, U.S. Atomic Energy Commission, August 10, 1966.
2. Uses of radioisotopes in medicine;SILVER;Nucleonics,1965
3. 118 Medical radioisotope cows;BRUCER;Isotopes and Radiation Technology,1965
4. Code of U.S. Federal Regulations. Title 10, Part 20:Standards for Protection Against Radiation; Part 35: Human Uses of Byproduct Material.
5. Recommendations of the International Commission on Radiological Protection, Report of Committee V, Handling and Disposal of Radioactive Materials in Hospitals and Medical Research Establishments. ICRP Publication 5, Pergamon Press (1964).