For citations:

Zhdanov R.I., Khabibullin I.M., Khammatova E.F., Aidarov V.I., Zhdanova S.I., Dvoenosov V.G., Khairullin R.N. Active longevity: long-term clinical observation. Russian Journal of Geriatric Medicine. 2020;(4):339-349. (In Russ.) https://doi.org/10.37586/2686-8636-4-2020-339-349