MALECZEK, Stanisław. “Optimisation of the Total Harmonic Distortions of the Acoustic Vacuum Tube Push-Pull Amplifier”. Archives of Acoustics 33, no. 1 (March 31, 2008): 103–109. Accessed March 4, 2026. https://acoustics.ippt.gov.pl/index.php/aa/article/view/636.