1. Carl, S. and Heikkila, S., On the Existence of Minimal and Maximal Solutions of Discontinuous Functional Sturm-Liouville Boundary Value Problems, J. Inequal. Appl., 2005, no. 4, pp. 403–412.
2. Bonanno, G. and Bisci, G.M., Infinitely Many Solutions for a Boundary Value Problem with Discontinuous Nonlinearities, Bound. Value Probl., 2009, art. ID 670675, 20 p.
3. Bonanno, G. and Buccellato, S.M., Two Point Boundary Value Problems for the Sturm-Liouville Equation with Highly Discontinuous Nonlinearities, Taiwanese J. Math., 2010, vol. 14, no. 5, pp. 2059–2072.
4. Pavlenko, V.N. and Potapov, D.K., Existence of a Ray of Eigenvalues for Equations with Discontinuous Operators, Sibirsk. Mat. Zh., 2001, vol. 42, no. 4, pp. 911–919.
5. Potapov, D.K., Estimation of the Bifurcation Parameter in Spectral Problems for Equations with Discontinuous Operators, Ufim. Mat. Zh., 2011, vol. 3, no. 1, pp. 43–46.