Necessary optimality conditions for a fractional multiobjective optimization problem Nazih Abderrazzak Gadhi, Khadija Hamdaoui, Mohammed El Idrissi and Fatima Zahra Rahou RAIRO-Oper. Res., 55 (2021) S1037-S1049 Published online: 02 March 2021 DOI: 10.1051/ro/2020049