@article{DAN_1961_138_1_a7,
     author = {V. I. Lebedev},
     title = {Dirichlet and {Neumann} problems on triangular and hexagonal grids},
     journal = {Doklady Akademii Nauk},
     pages = {33--36},
     publisher = {mathdoc},
     volume = {138},
     number = {1},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_138_1_a7/}
}