@article{PismaZhETF.49.251,
    title = {Formula for a Wilson loop},
    author = {D'yakonov, D. I. and Petrov, V. Yu.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {49},
    issue = {5},
    pages = {251},
    year = {1989},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_16891.shtml},
}