Bandyrskii, B. I., et al. “Generalization of Resonance Equations for the Laguerre- and Legendre-Type Polynomials to the Fourth-Order Equations”. Ukrains’kyi Matematychnyi Zhurnal, vol. 71, no. 11, Feb. 2026, pp. 1529-38, https://doi.org/10.3842/umzh.v71i11.1533.