@article{Mod-Cha-2023,
    author={Axel Modave and Théophile Chaumont-Frelet },
    title={A hybridizable discontinuous Galerkin method with 
           characteristic variables for Helmholtz problems },
    doi={10.1016/j.jcp.2023.112459 },
    journal={Journal of Computational Physics },
    year={2023 },
    month={11},
    volume={493 },
    pages={112459},
}