@article{PismaZhETF.50.309,
    title = {Four-loop $\beta$ function of supersymmetric Wess-Zumino-Witten model},
    author = {Deriglazov, A. A. and Ketov, S. V. and Pugai, Ya. P.},
    journal = {Письма в ЖЭТФ},
    volume = {50},
    issue = {7},
    pages = {309},
    year = {1989},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_17117.shtml},
}