1. NCRP 97a, Measurement of radon and radon daughters in air,1988
2. Factors affecting exhalation of radon from a gravelly sandy loam;Schery;J. Geophys. Res.,1984
3. NCRP 97b, Measurement of radon and radon daughters in air,1988
4. Radon migration in the ground: a supplementary review;Tanner,1980
5. Air chemistry and radioactivity;Junge,1963