Tomchuk, P., M. Brodyn, V. Volkov, and V. Lyakhovetskii. “Third-Order Optical Nonlinearity of Noble Metal Nanostructures”. Ukrainian Journal of Physics, Vol. 8, no. 1, Dec. 2019, p. 50, https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2019668.