@article{JETPL.98.247, title = {}, author = {, and , and , and Kats, E. I.}, journal = {JETP Lett.}, volume = {98}, issue = {4}, pages = {219}, year = {2013}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X13160078}, note = {[Pisma v ZhETF 98, 247 (2013)]} }