@article{DAN_1983_270_2_a7,
     author = {V. S. Ryaben'kii},
     title = {Generalization of {Calder\'on} projections and boundary equations on the basis of the notion of precise trace},
     journal = {Doklady Akademii Nauk},
     pages = {288--292},
     publisher = {mathdoc},
     volume = {270},
     number = {2},
     year = {1983},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1983_270_2_a7/}
}