[21] Y. Zhang, D. V. Voronine, S. Qiu, S. Qiu, A. M. Sinyukov, M. Hamilton, A. V. Sokolov, Z. Zhang, M. O. Scully. Quantum limit in subnanometre-gap tip-enhanced nanoimaging of few-layer MoS2(2015).
[26] P. B. Johnson. Optical constants of the noble metals. Phys. Rev. B, 6, 4370-4379(1972).
[28] L. Novotny, B. Hecht, O. Keller. Principles of Nano-Optics(2012).