Kažys, R., R. Rekuvienė, and E. Žukauskas. “Numerical Investigation of Ultrasonic Wave Propagation in Tapered Waveguides”. Elektronika Ir Elektrotechnika, vol. 19, no. 6, June 2013, pp. 55-58, doi:10.5755/j01.eee.19.6.4563.