Olga Brezhneva Yuri Evtushenko Vlasta Malkova Alexey Tret'yakov Singular Optimization Problems and p-Factor Approach for Their Analysis. 31-42 2024 OPTIMA https://doi.org/10.1007/978-3-031-79119-2_3 conf/optima/2024 db/conf/optima/optima2024.html#BrezhnevaEMT24 streams/conf/optima