@article{JETPL.97.469, title = {}, author = {, and Zagorodnev, I. V.}, journal = {JETP Lett.}, volume = {97}, issue = {7}, pages = {404}, year = {2013}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X13070060}, note = {[Pisma v ZhETF 97, 469 (2013)]} }