@article{PismaZhETF.50.205,
    title = {NMR-echo study of topological phase in two-level system},
    author = {Lisin, V. N. and Fedoruk, G. G. and Khaimovich, E. P.},
    journal = {Письма в ЖЭТФ},
    volume = {50},
    issue = {4},
    pages = {205},
    year = {1989},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_17087.shtml},
}