1. Contribution of natural terrestrial sources to the total radiation dose to man;Auxier,1973
2. In Situ Ge (Li) and NaI (TI) gamma-ray spectrometry;Beck,1972
3. Further studies of external environmental radiation;Beck,1966
4. Studies of the natural background radiation in Italy;Cardinale;Health Physics,1971
5. High pressure argon ionization chamber systems for the measurement of environmental radiation exposure rates;De Campo,1972