@article{JETPL.101.19, title = {}, author = {, and Kats, E. I.}, journal = {JETP Lett.}, volume = {101}, issue = {1}, pages = {17}, year = {2015}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X1501004X}, note = {[Pisma v ZhETF 101, 19 (2015)]} }