@article{TRSPY_1959_53_a4,
     author = {V. P. Il'in},
     title = {Estimate of error in the {Ritz} method for ordinary differential equations},
     journal = {Informatics and Automation},
     pages = {43--63},
     publisher = {mathdoc},
     volume = {53},
     year = {1959},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TRSPY_1959_53_a4/}
}