1. M. Tecotzky , in 1787–1987 Two Hundred Years of Rare Earths, ed. K. A. Gschneidner and J. Capellen, Rare Earths Information Center, Iowa State University, Ames, IA, 1987, p. 23.
2. I. Hemmilä , 2nd Int. Conf. F-Elements (ICFE-2), Helsinki, Finland, 1994, Book of Abstracts, p. 40.
3. G. S. Pomrenke , 20th RE Research Conf., Monterey, USA, 1993, Book of Abstracts, p. 12.
4. Has the (LnO)nn+ (Ln Lanthanide) complex cation a spectroscopic “fingerprint”?
5. Preparation and optical properties of europium-activated rare earth oxysulfates