Лютак, І. З. “Control of Defects in the Walls of Pipelines by the Ultrasonic Directed Circular Waves”. METHODS AND DEVICES OF QUALITY CONTROL, no. 2(23) (December 2, 2009): 20–24. Accessed May 20, 2024. https://mpky.nung.edu.ua/index.php/mpky/article/view/299.