@article{PismaZhETF.41.79,
    title = {Exact solution of the O(3) nonlinear two-dimensional $\sigma$-model},
    author = {Wiegmann, P. B.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {41},
    issue = {2},
    pages = {79},
    year = {1985},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_21926.shtml},
}