1. ‘Microwave signal processing devices’, University of Leeds research report, LU/EE/67/12, US Office of Aerospace Research, Rome Air Development Center, August, 1967 p. 131–200 Contract AF 61(025)-925, chaps. 6 and 7
2. Collin, R.: Field theory of guided waves, (McGraw-Hill 1960),chap. 6,