P. Dymek, A. Płaneta, M. Ptak, “Commuting conjugations for operators being far from unitary operators”, Journal of Mathematical Analysis and Applications, 2025, 129699
Francisco Marcellán, Nikta Shayanfar, “OPUC, CMV matrices and perturbations of measures supported on the unit circle”, Linear Algebra and its Applications, 485 (2015), 305