2 citations to https://www.mathnet.ru/rus/tm3960

1. S. Baranzini, “Functional determinants for the second variation”, J. Fixed Point Theory Appl., 26:2 (2024)    
2. S. Baranzini, “Operators arising as second variation of optimal control problems and their spectral asymptotics”, J. Dyn. Control Syst., 29:3 (2023), 659