1. J. Wang, H. P. Li, and R. Stevens, “Review. Hafnia and hafnia-toughened ceramics,” J. Mat. Sci., 27, No. 12, 5397–5430 (1992).
2. X. Q. Cao, R. Vassen, F. Tietz, and D. Stoever, “New double-ceramic-layer thermal barrier coatings based on zirconia-rare earth composite oxides,” J. Eur. Ceram. Soc., 26, 247–251 (2006).
3. E. R. Andrievskaya, Phase Equilibria in the Systems of Hafnium, Zirconium, and Yttrium Oxides with Rare Earth Oxides [in Russian], Naukova Dumka, Kiev (2010), p. 470.
4. A. Rouanet, “Contribution a l’etude des systemes zirconia–oxydes des lanthanides au voisinage de la fusion: memoire de these,” Rev. Int. Hautes Temper. Refract., 8, No. 2, 161–180 (1971).
5. J. Lefevre, “Some structural modifications of fluorite-type phase in the systems based on ZrO2 or HfO2,” Ann. Chim., 8, No. 1–2, 254–256 (1963).