@article{PismaZhETF.49.685,
    title = {Nonzero state density in superconductors with a high transition temperature},
    author = {Volovik, G. E.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {49},
    issue = {12},
    pages = {685},
    year = {1989},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_17023.shtml},
}