@article{PismaZhETF.46.8,
    title = {An explicit equation for a two-loop measure in a heterotic-string model},
    author = {Knizhnik, V. G.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {46},
    issue = {1},
    pages = {8},
    year = {1987},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_18488.shtml},
}