1. Tanner AB (1980) In: Gendsell TF, Lowder WM (eds) The natural radiation environment III. University of Chicago Press, Chicago, p 5
2. Nazaroff WW, Moed BA, Sextro RG (1988) Soil as a source of indoor radon: Generation, migration and entry. In: Nazaroff WW, Nero AV (eds) Radon and its decay products in indoor air. Wiley-Interscience, New York, pp 57–112
3. Rogers VC, Nielson KK (1991) Multiphase radon generation and transport in porous materials. Health Phys 60:807
4. Nazaroff WW (1992) Radon transport from soil to air. Rev Geophys 30(2):137–160
5. Elzain AA, Mohammed YSh, Mohamed KS, Mohamed-Ali AM (2016) A study of radium concentration and radon exhalation rate in soil samples from Kassala Town, Sudan Using SSNTDs. Am J Phys Appl 4(4):84–89