@article{PismaZhETF.50.341,
    title = {Central expansion of Lie algebra of differential operators on a circle and W algebras},
    author = {Radul, A. O.},
    journal = {Письма в ЖЭТФ},
    volume = {50},
    issue = {8},
    pages = {341},
    year = {1989},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_17125.shtml},
}