@article{etna_vol48_pp264-285, author = {Radek Tezaur and Petr Van\v{e}k}, title = {Improved convergence bounds for two-level methods with an aggressive coarsening and massive polynomial smoothing}, journal = {Electron. Trans. Numer. Anal.}, volume = {48}, year = {2018}, pages = {264--285}, doi = {10.1553/etna_vol48s264}, }