@article{PismaZhETF.58.925,
    title = {Causality and Kallen-Lehmann-like representation of the fermionic string propagator},
    author = {Fainberg, V. Ya. and Fil'kov, A. L.},
    journal = {Письма в ЖЭТФ},
    volume = {58},
    issue = {11},
    pages = {925},
    year = {1993},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_18031.shtml},
}