1. “Methods of Theoretical Physics; Part I.”;Morse,1953
2. Application of finite element method to the solution of Helmholtz's equation;Arlett;Proc. IEE,1968
3. Finite element solution of the homogeneous waveguide problems;Silvester;Alta Frequenza,1969
4. Waveguide solutions by the finite element method;Ahmad;Radio Electron. Eng.,1969
5. Harbour oscillation: A numerical treatment for undamped natural modes;Taylor;Proc. Inst. Civil Eng.,1969