@article {Chaumont-FreletVerfuerth2021,
    AUTHOR = {Chaumont-Frelet, Th\'{e}ophile and Verf\"{u}rth, Barbara},
     TITLE = {A generalized finite element method for problems with
              sign-changing coefficients},
   JOURNAL = {ESAIM Math. Model. Numer. Anal.},
  FJOURNAL = {ESAIM. Mathematical Modelling and Numerical Analysis},
    VOLUME = {55},
      YEAR = {2021},
    NUMBER = {3},
     PAGES = {939--967},
      ISSN = {2822-7840},
   MRCLASS = {65N30 (35J20 65N12 65N15 78A48)},
       DOI = {10.1051/m2an/2021007},
       URL = {https://doi.org/10.1051/m2an/2021007},
}