@article{ZNSL_1999_259_a0,
     author = {A. A. Arkhipova and O. A. Ladyzhenskaya},
     title = {On a modification of {Gehring} lemma},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {7--18},
     publisher = {mathdoc},
     volume = {259},
     year = {1999},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1999_259_a0/}
}