1. New phenomenon in narrow Ge p–n junctions;Esaki;Phys. Rev.,1959
2. Tunnel diodes as high-frequency devices;Sommers;Proc. IRE,1959
3. Low-noise tunnel-diode amplifier;Chang;Proc. IRE,1959
4. (a) Chang, K. K. N. Negative conductance diode amplifier. U.S. Patent 3,127,567 (1964).
5. (b) Chang, K. K. N. Frequency converter. U.S. Patent 3,125,725 (1964).