@article{JETPL.99.231,
    title = {},
    author = {Tkachenko, O. A. and Tkachenko, V. A.},
    journal = {JETP Lett.},
    volume = {99},
    issue = {4},
    pages = {204},
    year = {2014},
    doi = {},
    url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X14040067},
    note = {[Pisma v ZhETF 99, 231 (2014)]}
}