Mukhametkarimov, Y., Z. Kudyshev, A. Davletov, I. Gabitov, and A. Maimistov. “Second Harmonic Generation in Dissipative Metamaterials”. Recent Contributions to Physics (Rec.Contr.Phys.), vol. 42, no. 3, Sept. 2012, pp. 5-62, https://bph.kaznu.kz/index.php/zhuzhu/article/view/709.