For citations:

Vegner E.A., Krivoshapova K.E., Barbarash O.L. Challenges in diagnosing frailty syndrome in the elderly population of different countries. Complex Issues of Cardiovascular Diseases. 2020;9(4):95-104. (In Russ.) https://doi.org/10.17802/2306-1278-2020-9-4-95-104