1 Gao Yutang . General statistic methods in environmental monitoring. Beijing : Atomic Energy Press , 1980: 56
2 Ren Canjun, Zhou Baiming translated. Beijing : Atomic Energy Press , 1986; 52
UNSCEAR 1977 Report
.3 Beck H L .
The physics of environmental gamma radiation fields
. In: The natural radiation environment II. U.S. Energy Research and Development Administration Report, CONF-720805. 1972: 101