1. Glover, G.H.: Microwave measurements of the velocity-field characteristic ofn-type indium phosphide,
2. Data from the Allen Clark Research Centre, The Plessey Co. Ltd.
3. Marcuvitz, N.: The waveguide handbook, (McGraw-Hill 1951)
4. Whittaker, E.T., and Watson, G.N.: A course of modern analysis, (CUP 1945), p. 229 et seq.