@article{PismaZhETF.50.280,
    title = {Adiabatic approximation and the condition for the existence of a small polaron},
    author = {Aleksandrov S.., A. and Krebs, A. B.},
    journal = {Письма в ЖЭТФ},
    volume = {50},
    issue = {6},
    pages = {280},
    year = {1989},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_17109.shtml},
}