@article{etna_vol51_pp432-450, author = {Axel Klawonn and Martin Lanser and Oliver Rheinbach and Janine Weber}, title = {Preconditioning the coarse problem of BDDC methods ‐ three-level, algebraic multigrid, and vertex-based preconditioners}, journal = {Electron. Trans. Numer. Anal.}, volume = {51}, year = {2019}, pages = {432--450}, doi = {10.1553/etna_vol51s432}, }