... like: Lanthanum Oxide, Cerium Oxide, Praseodymium Oxide, Neodymium Oxide, PR+ND Oxide, Samarium Oxide, Europium Oxide, Gadolinium Oxide, Yttrium Oxide, Terbium Oxide, Dysprosium Oxide, Holmium Oxide, Erbium Oxide, Thulium Oxide, Ytterbium Oxide, Lutetium Oxide and so on ...