1. UNSCEAR, Sources and Effects of Ionizing Radiation. Report to the General Assembly with Scientific Annexes, United Nations Scientific Committee on the Effects of Atomic Radiation, New York, 2000.
2. D. B. Henschel, Radiat. Prot. Dosim., 56 (1994) 21.
3. C. S. Li, P. K. Hopke, Health Phys., 61 (1991) 785.
4. F. J. Offermann, R. G. Sextro, W. J. Fisk, D. T. Grimsrud, W. W. Nazaroff, A. V. Nero, K. L. Revzan, J. Yater, Control of Respirable Particles in Indoor Air with Portable Air Cleaners, Report LBL-17939, Lawrence Berkeley Laboratory, Berkeley, California, 1984.
5. S. Tokonami, T. Matsuzawa, T. Ishikawa, T. Iimoto, H. Yonehara, T. Yamada, Radioisotopes, 52 (2003) 285.