R Kotzé, R Haldenwang, V Fester, and W Rössle. “In-Line Rheological Characterisation of Wastewater Sludges Using Non-Invasive Ultrasound Sensor Technology”. Water SA 41, no. 5 October (October 29, 2015). Accessed May 3, 2024. https://watersa.net/article/view/11027.