@article{DAN_1961_139_5_a5,
     author = {P. I. Lizorkin},
     title = {The {Green's} $E$-function of a {Beltrami} operator and some variational problems},
     journal = {Doklady Akademii Nauk},
     pages = {1052--1055},
     publisher = {mathdoc},
     volume = {139},
     number = {5},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_139_5_a5/}
}