1. 1. Kryzhanivs'kyi, E. I., Hrabovs'kyi, R. S. & Mandryk, O. M. (2013). Estimation of the serviceability of oil and gas pipelines after long-term operation according to the parameters of their defectiveness. Materials Scien ce. 49, No. 1, pp. 117-123. https://doi.org/10.1007/s11003-013-9590-6
2. 2. State Standard of Ukraine: DSTU N B V.2.3-21: 2008. (2008). Determination of residual strength of main pipelines with defects: regulatory and technical material. Кyiv: Minrehionbud Ukraine. 64 p. (in Ukrainian).
3. 3. State standard of Ukraine: DSTU EN ISO 16826:2015 (2015). Non-destructive testing. Ultrasonic control. Examination for discontinuities perpendicular to the surface. Кyiv: DP «UkrNDNC». 73 p. (in Ukrainian).
4. 4. Butrak, І. (2015). The influence of harmonic wave on the concentrationof stresses in the infinite solid with pliable disk-shaped inclusions. Fizyko-matematychne modeliuvannia ta informatsiini tekhnolohii. 21, pp. 30-38 (in Ukrainian).
5. 5. Panasiuk, V. V., Stadnyk, М. М. & Sylovaniuk, V. P. (1986). Stress concentration in three-dimensional bodies with thin inclusions. Kyiv: Naukova Dumka. (in Ukrainian).