@article{PismaZhETF.39.211,
    title = {Negative-U tunnelling centers and photostimulated reactions in semiconductors},
    author = {Bagraev, N. T. and Mashkov, V. A.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {39},
    issue = {5},
    pages = {211},
    year = {1984},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_19459.shtml},
}