1. Andjelov, M., 1998. Assessment of capacity of soil gas radon monitoring in various active faults zones for prediction of earthquake occurrence, CEC-INCO-COPERNICUS, Annual Progress Report for the Period 1997–1998, Athens, Greece.
2. Birchfard, G.F., Libby, W.F., 1976. An inexpensive radon earthquake prediction concept, Eos Trans. Am. Geophys. Union 57(12) 957 (Abstract).
3. Gas phase radon anomalies, Eos Trans;Birchfard;Am. Geophys. Union,1977
4. Atmospheric pressure effects on 222Rn transport across the earth–air interface;Clements;J. Geophys. Res.,1974
5. Estimation of the size of earthquake preparation zones;Dobrovolsky;Pure. Appl. Geophys.,1979