@article{JETPL.106.780, title = {}, author = {Mavrogordatos, Th. K.}, journal = {JETP Lett.}, volume = {106}, issue = {12}, pages = {815}, year = {2017}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X17240110}, note = {[Pisma v ZhETF 106, 780 (2017)]} }