For citations:

Birjukov S.G., Kovalenko O.I., Orlov A.A. Status and development prospects of standard means for reproducing units of volumetric activity of radon and thoron and radon flux density from the soil surface. Izmeritel`naya Tekhnika. 2020;(1):68-72. (In Russ.) https://doi.org/10.32446/0368-1025it.2020-1-69-73