Morán-López, A., J. Córcoles, and J. A. Ruiz-Cruz,  "Efficient computation and orthonormalization of multiple TEM numerical modes arising from FEM for microwave computer-aided-design",  Numerical Electromagnetic and Multiphysics Modeling and Optimization for RF, Microwave, and Terahertz Applications (NEMO), 2017 IEEE MTT-S International Conference on: IEEE, pp. 197?199, 2017.