@article{VMP_2009_10_1_a4,
     author = {A. N. Bogolyubov and A. A. Panin},
     title = {An error estimate for approximate solutions to elliptic equations with non-coercive bilinear form},
     journal = {Numerical methods and programming},
     pages = {34--48},
     publisher = {mathdoc},
     volume = {10},
     number = {1},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMP_2009_10_1_a4/}
}