@article{DAN_1962_147_6_a17,
     author = {S. I. Vetchinkin},
     title = {A method of determining optimal wave functions for an approximate calculation of matrix elements},
     journal = {Doklady Akademii Nauk},
     pages = {1328--1331},
     publisher = {mathdoc},
     volume = {147},
     number = {6},
     year = {1962},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1962_147_6_a17/}
}