Svilainis, Linas, Andrius Chaziachmetovas, and Tomas E. Gomez Alvarez-Arenas. 2019. “Ultrasonic Air Coupled Transducer Output Impedance Measurement Technique”. Elektronika Ir Elektrotechnika 25 (1):18-25. https://doi.org/10.5755/j01.eie.25.1.22731.