N. Caspary, E. V. Savchenko, A. Thoma, A. Lammers, і V. E. Bondybey, «Optical spectra of CuO₂ and matrix effect upon its structure: Low-Temperature Physics and Chemistry in Cryomatrice», Fiz. Nizk. Temp., вип. 26, вип. 9-10, с. 1001–1010, Вер 2000.