Lubenets, S. V., Natsik, V. D., Fomenko, L. S., Kaufmann, H. .-J., Bobrov, V., & Izotov, A. N. (1997). Influence of oxygen content and structural defects on low-temperature mechanical properties of high-temperature superconducting single crystals and ceramics. ФІЗИКА НИЗЬКИХ ТЕМПЕРАТУР, 23(8), 902–908. https://doi.org/10.1063/1.593440