Becher, P.F. Strong, Tough Ceramics Containing Microscopic Reinforcements: Tailoring In-Situ Reinforced Silicon Nitride Ceramics, article, June 27, 1999; (https://digital.library.unt.edu/ark:/67531/metadc678626/m1/1/: accessed December 18, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .