@article{PismaZhETF.50.434,
    title = {The RVB model as the problem of the surface of a quantum crystal},
    author = {Levitov, L. S.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {50},
    issue = {10},
    pages = {434},
    year = {1989},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_17152.shtml},
}