H. Yar’Adua, Kabir., et al. “Investigating the Effect of Varying Tubing Air Concentration During the Descaling of Petroleum Production Tubing Using Multiple High-Pressure Nozzles”. American Scientific Research Journal for Engineering, Technology, and Sciences, vol. 76, no. 1, Feb. 2021, pp. 185-98, https://asrjetsjournal.org/American_Scientific_Journal/article/view/6574.