@article{etna_vol54_pp534-557, author = {Luis Garc{\'i}a Ramos and Olivier S\`{e}te and Reinhard Nabben}, title = {Preconditioning the Helmholtz equation with the shifted Laplacian and Faber polynomials}, journal = {Electron. Trans. Numer. Anal.}, volume = {54}, year = {2021}, pages = {534--557}, doi = {10.1553/etna_vol54s534}, }