FUGOL, I. Y., V. N. SAMOVAROV, Y. I. RYBALKO, і V. M. ZHURAVLEV. «Luminescence of Charge-Sensitive Oxygen Centers in High-Temperature Super Conductors: The Effect of Superconducting Transition». ФІЗИКА НИЗЬКИХ ТЕМПЕРАТУР, вип. 16, вип. 5, Травень 1990, с. 580-3, http://80.92.230.95/index.php/fnt/article/view/f16-0580e.