@article{ZNSL_1967_5_a10,
     author = {N. N. Ural'tseva},
     title = {On impossibility of $W_q^2$-estimates for the elliptic equations in several variables with discontinuous coefficients},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {250--254},
     publisher = {mathdoc},
     volume = {5},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1967_5_a10/}
}