@article{ZNSL_1974_48_a5,
     author = {S. G. Mikhlin},
     title = {Variational-difference approximation},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {32--188},
     year = {1974},
     volume = {48},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1974_48_a5/}
}