@Misc{ 
  ButCasMae25,
  author = { Buttazzo, Giuseppe and Casado-Diaz, Juan and Maestre, Faustino },
  title = { Optimal sources for elliptic PDEs },
  journal = {  },
  year = { 2025 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/7275/ },
  note = { cvgmt preprint}
}