7WHO. WHO Handwork on Indoor Radon: A Public Health Perspective. Switzerland: WHO, 2009.
8Tokonami S, Sanada T, Yang M. Contribution from thoron on the response of passive radon detectors [J]. Health Phys, 2001, 80 (6): 612 - 615.
9WiegandJ, Feige S, Quingling X, et al. Radon and thoron in cave dwellings (Yan'an, China) [J]. Health Phys, 2000, 78 (4) :438- 444.
10Butterweck G, Schuler Ch, Paul A, et al. Intercomparison exercise of the PTb, BfS, MPA and PSI calibration facilities for radon [J].Radiat Prot Dosimetry , 2002, 98 (2): 219-222.
