@book{
international2021iaea,
title={Application of a Graded Approach in Regulating the Safety of Radiation Sources},
series={TECDOC Series},
number={1974},
year={2021},
isbn={978-92-0-127421-2},
url={http://www.dgdingfa.net/publications/14908/application-of-a-graded-approach-in-regulating-the-safety-of-radiation-sources},
publisher={INTERNATIONAL ATOMIC ENERGY AGENCY},
address={Vienna}
}