Tavlarides, L.L. & Sangani, Ashok. Acoustic Probe for Solid-Gas-Liquid Suspension, report, September 14, 2003; (https://digital.library.unt.edu/ark:/67531/metadc780899/m1/1/: accessed November 19, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .