@article{DAN_1988_300_6_a16,
     author = {V. P. Bykov},
     title = {Basisless variational method},
     journal = {Doklady Akademii Nauk},
     pages = {1353--1355},
     publisher = {mathdoc},
     volume = {300},
     number = {6},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1988_300_6_a16/}
}