@article{SM_1980_37_3_a6,
     author = {Yu. B. Orochko},
     title = {Smooth approximation of selfadjoint differential operators of divergence form with bounded measurable coefficients},
     journal = {Sbornik. Mathematics},
     pages = {389--401},
     publisher = {mathdoc},
     volume = {37},
     number = {3},
     year = {1980},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1980_37_3_a6/}
}