@article{PismaZhETF.47.196, title = {Proof of the metallic nature of the chemical bond and coexistence of magnetism and superconductivity in the $Y_{1-x}Fe_xBa_2Cu_3O_{\delta}$ system (0<x<0.5)}, author = {Lyubutin, I. S. and Smirnovskaya, E. M. and Terziev, V. G. and Shapiro, A. Ya.}, journal = {Письма в ЖЭТФ}, volume = {47}, issue = {4}, pages = {196}, year = {1988}, doi = {}, url = {http://jetpletters.ru/ps/0/article_16493.shtml}, }