Wongsaroj, Wongsakorn, et al. “Ultrasonic Velocity Profiler for the Measurement of a Bubbly Flow Velocity Vector in Small Channels”. International Journal of Integrated Engineering, vol. 15, no. 4, Oct. 2023, pp. 77-88, https://penerbit.uthm.edu.my/ojs/index.php/ijie/article/view/10922.