[1] Vermeulen A J. Influence of inhomogeneous refractive indices in multilayer anti-reflection coatings. Optica Acta, 1976,23(1):71
[7] Akahira N, Ohta T, Yamada N, et al. Sub-oxide thin film for an optical recording disk. In:Proc. SPIE, 1982, 329:195-200