@Article{NM-14-31, author = {Z. Chen, B. Wu and Y. Xu}, title = {Multilevel augmentation methods for solving operator equations}, journal = {Numerical Mathematics, a Journal of Chinese Universities}, year = {2015}, volume = {14}, number = {1}, pages = {31--55}, abstract = {}, issn = {}, doi = {https://doi.org/}, url = {http://global-sci.org/intro/article_detail/nm/8000.html} }