Here are three of the most cited articles from European Journal of Operational Research published since 2020, extracted from Scopus.
 

• Machine learning for combinatorial optimization: A methodological tour d'horizon
  Yoshua Bengio, Andrea Lodi, Antoine Prouvost, 290(2), 405-421, avril 2021.

• A concise guide to existing and emerging vehicle routing problem variants
  Thibaut Vidal, Gilbert Laporte, Piotr Matl, 286(2), 401-416, octobre 2020.

• Performance indicators in multiobjective optimization
  Charles Audet, Jean Bigeon, Dominique Cartier, Sébastien Le Digabel et Ludovic Salomon, 292(2), 397-422, juillet 2021.