1.
AIZICOVICI, Sergiu, PAPAGEORGIOU, Nikolaos S. and STAICU, Vasile. Nonlinear periodic system with unilateral constraints. Topological Methods in Nonlinear Analysis. Online. 9 November 2019. Vol. 54, no. 2B, pp. 871 - 885. [Accessed 21 December 2025].