1. Jianshu Cao, Yang Li, Li Lin, et al., Nondestructive testing technology for natural gas pipeline, NDT Int., 2013, vol. 35, no. 5, pp. 20–25.
2. Ayesha Khalid, Ali M-Ghazanfar, Khan Dr.-Tariq-Mairaj-Rasool, et al., Assessment and characterization of welded mild steel (E-6013) using ultrasonic testing and Hilbert Huang transform, Russ. J. Nondestr. Test., 2021, vol. 57, no. 5, pp. 401–407.
3. Donglin Tang, Zibing Wei, Feng Pan, et al., Ultrasonic internal detection of pipeline corrosion based on PCA and SVM, Chin. J. Sens. Transducers, 2018, vol. 31, no. 7, pp. 1040–1045.
4. Jingpin Jiao, Quan Cheng, Deyu Liu, et al., Research on corrosion grade evaluation method of tank floor based on ultrasonic detection, China Spec. Equip. Safety, 2017, vol. 33, no. 8, pp. 29–34.
5. Santos, J.-B. and Perdigao, F., Automatic defects classification—A contribution, NDT & E Int., 2001, vol. 34, no. 5, pp. 313–318.