@article{RM_1975_30_4_a6,
     author = {L. Nirenberg},
     title = {Lectures on linear partial differential equations},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     year = {1975},
     volume = {30},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1975_30_4_a6/}
}