1. M. E. Hines, ?High-frequency negative-resistance circuit principles for Esaki diode applications?,Bell System Technical Journal, Vol. 34, pp. 477?513, May 1960.
2. T. Yamamoto, A. Shimizu and J. Nishizawa, ?Theoretical analysis of the amplification by the diode with homogeneously distributed structures?,Report Res. Inst. Elec. Comm., Tohoku University, Sendai, Japan, Vol. 14, pp. 63?78, 1962.
3. T. A. Midford and H. C. Bowers, ?A two-port IMPATT diode travelling wave amplifier?,Proc. IEEE, Vol. 56, pp. 1724?1725, October 1968.
4. M. Franz and J. B. Beyer, ?The traveling wave IMPATT mode?,IEEE Trans. Microwave Theory and Techniques, Vol. MTT-26, pp. 681?685, November 1978.
5. K. Yokoo and S. Ono, ?Electronically tunable Gunn diode oscillator?,Electronics and Communications in Japan, Vol. 58-B, pp. 56?65, October 1975.