1. Fleischmann, M., Hendra, P.J., and McQuillan, A.J., Chem. Phys. Lett., 1974, vol. 26, no. 2, p. 163.
2. Otto, A., Mrozek, I., Grabhorn, H., and Akemann, W., J. Phys.: Condens. Matter, 1992, vol. 4, p. 1143.
3. Kukushkin, V.I., Van’kov, A.B., and Kukushkin, I.V., JETP Lett., 2013, vol. 98, p. 64.
4. Moskovits, M., Rev. Mod. Phys., 1985, vol. 57, p. 783.
5. Le Ru, E.C. and Etchegoin, P.G., Principles of Surface-Enhanced Raman Spectroscopy, New York: Elsevier, 2009.