Muradov, A. D. “INFLUENCE OF COLD TEMPERATURE ANNEALING ON OPTICAL PROPERTIES OF SYSTEM «POLYIMIDE – YBa2Cu3O6+x»”. Recent Contributions to Physics, vol. 2009, no. 4, Dec. 2009, pp. 78-82, https://bph.kaznu.kz/index.php/zhuzhu/article/view/230.