Mandra, A., et al. “Modeling of Ultrasonic Guided Waves Propagation in a Waveguide With Cross-Section of Finite Size”. JOURNAL OF HYDROCARBON POWER ENGINEERING, vol. 1, no. 1, Dec. 2014, pp. 58-65, https://ogpe.nung.edu.ua/index.php/jhpe/article/view/13.