@article{NUMA_1991__60_4_133596,
     author = {Roland W. Freund and N.M. Nachtigall},
     title = {QMR: a quasi-minimal residual method for {non-Hermitian} linear systems.},
     journal = {Numerische Mathematik},
     pages = {315--340},
     publisher = {mathdoc},
     volume = {60},
     number = {4},
     year = {1991},
     zbl = {0754.65034},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1991__60_4_133596/}
}