V. Tarenkov, V. Krivoruchko, A. Shapovalov, A. Kalenyuk, E. Zhitlukhina, P. Febvre, and M. Belogolovskii, Possible observation of Leggett-like modes in a coherent two-phase medium, Low Temp. Phys. 49, 855–859, (2023) [Fiz. Nyzk. Temp. 49, 938–942, (2023)] DOI: https://doi.org/10.1063/10.0019697.