@article{PismaZhETF.31.138,
    title = {Interaction of instantons and anti-instantons in a nonlinear 0(3)$\sigma$ model and a certain exactly solvable fermion theory},
    author = {Bukhvostov, A. P. and Lipatov, L. N.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {31},
    issue = {2},
    pages = {138},
    year = {1980},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_20259.shtml},
}