Courtright, E.L. & Prater, J.T. Oxygen permeability of several ceramic oxides above 1200 degrees C, article, January 1, 1992; (https://digital.library.unt.edu/ark:/67531/metadc1102708/m1/1/: accessed November 16, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .