'Adjoint sensitivity analysis with dispersive materials' (Electromagnetic Waves, 2017), 'Adjoint Sensitivity Analysis of High Frequency Structures with MATLAB®', Chap. 6, pp. 151-174, DOI: 10.1049/SBEW525E_ch6
IET Digital Library, https://digital-library.theiet.org/;jsessionid=5effvkqqi3p3s.x-iet-live-01content/books/10.1049/sbew525e_ch6