@article{ZNSL_1997_243_a12,
     author = {S. I. Repin},
     title = {A posteriori error estimation for nonlinear variational problems by duality theory},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {201--214},
     year = {1997},
     volume = {243},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1997_243_a12/}
}