1. 2G. R. Houten, J. F. White, and J. M. Botje , "Formation of Alumina Coatings on Beryllia by Vapor Deposition ,"U. S. Atomic Energy Comm., APEX-699, 78 pp. (1961 ).
2. 3K. H. Jack, G. W. Stephenson, and J. A. Winterburn , "Refractory Oxide Crystals ," Admiralty Contract Report, No. RP 9-15; Wallsend, Northumberland, Gt. Britain (1959 ).