Obukhovskii, Valeri, et al. “On a Random Topological Characteristic for Inclusions With Nonlinear Fredholm Operators: Application to Some Classes of Feedback Control Systems”. Advances in Systems Science and Applications, vol. 23, no. 3, Oct. 2023, pp. 48-65, doi:10.25728/assa.2023.23.3.1390.