@article{PismaZhETF.79.569,
    title = {Vacuum expectation values from        fusion of vertex operators},
    author = {Pugai, Y.},
    journal = {Письма в ЖЭТФ},
    volume = {79},
    issue = {10},
    pages = {569},
    year = {2004},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_5386.shtml},
}