For citations:

Biryukov S.G., Kovalenko O.I., Orlov A.A. State primary standard of units of volumetric activity of radioactive aerosols, radon, thoron and radon flux density GET 39-2021. Izmeritel`naya Tekhnika. 2022;(8):3-8. (In Russ.) https://doi.org/10.32446/0368-1025it.2022-8-3-8