@article{MZM_1989_45_2_a6,
     author = {L. A. Leont'eva},
     title = {Generalized derivative in an arbitrary domain},
     journal = {Matemati\v{c}eskie zametki},
     pages = {60--64},
     publisher = {mathdoc},
     volume = {45},
     number = {2},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1989_45_2_a6/}
}