@article{JETPL.101.925, title = {}, author = {, }, journal = {JETP Lett.}, volume = {101}, issue = {12}, pages = {825}, year = {2015}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X15120103}, note = {[Pisma v ZhETF 101, 925 (2015)]} }