@article{DAN_1993_329_5_a2,
     author = {V. M. Deundyak and I. B. Simonenko and V. A. Stukopin},
     title = {Homotopic classification of families of {Noether} singular operators},
     journal = {Doklady Akademii Nauk},
     pages = {540--542},
     publisher = {mathdoc},
     volume = {329},
     number = {5},
     year = {1993},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1993_329_5_a2/}
}