@article{DAN_1967_176_6_a6,
     author = {I. A. Kipriyanov},
     title = {Self-adjoint extensions of certain singular partial differential operators},
     journal = {Doklady Akademii Nauk},
     pages = {1236--1239},
     publisher = {mathdoc},
     volume = {176},
     number = {6},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1967_176_6_a6/}
}