1. High Efficiency Class C Amplifier;Wood,1969
2. Operation of Vacuum-Tube Generator on Detuned Resonant Circuit;Khmelnitsky,1962
3. High-Efficiency Radio-Frequency Power Amplifiers;Ewing;Ph.D. Dissertation, Oregon State University,,1964
4. Amplifier Has 85% Efficiency while Providing up to 10 Watts Power over a Wide Frequency Band;Lohrmann;Electronic Design,1966
5. Switching Mode of High Frequency Power Amplifiers (in Russian);Artym;Radiotekhnika,1969