1. Huxley, L.G.H.: A survey of the principles and practice of waveguides, (Cambridge 1947), p. 147
2. Marcuvitz, N.: Waveguide handbook, (McGraw Hill, MIT Radiation Laboratory Series 10 1951), p. 229
3. Monigomery, C.G., Dicke, R.H., and Purcell, E.M.: Principles of microwave circuits, (McGraw-Hill, MIT Radiation Laboratory Series 8 1948), p. 166–167