@article{PismaZhETF.32.419,
    title = {Excitonic insulator as a ferroelectric material},
    author = {Batyev, E. G. and Borisyuk, V. A.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {32},
    issue = {6},
    pages = {419},
    year = {1980},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_21726.shtml},
}