1. Matsen, J.M.: Powder Technol. 7, 93–96 (1993)
2. Richards, J.C.: Brit. Coal Utilities Res. Assoc. Monthly Bull. 28, 465–480 (1964)
3. Holtkamp, W.C.A., Kelly, F.T., Shingles, T.: Chemistry in South Africa, March, pp. 44–46 (1977)
4. Knowlton, T.M.: In: Littman, H. (ed.) National Science Foundation Workshop on Fluidization and Fluid Particle Systems – Research Needs and Properties, Rensselaer Polytechnic Institute (1979)
5. Teo, C.S., Leung, L.S.: J. Pipelines 2, 187–197 (1982)