1. P. Pascal, Nouveau traite de chimie minerale, Tom 14, VII/2, Masson, Paris 1959.
2. L. N. Komissarova, Soedineniya redkozemel'nyh elementov. Sulfatiy, selenatiy, telluratiy, khromatiy, Nauka, Moskow 1986.
3. V. B. Jordanovska and J. Siftar, Thermochim. Acta, 221 (1993) 79.
4. V. Jordanovska and J. Siftar, Thermochim. Acta, 195 (1992) 27.
5. V. Jordanovska, Contributions, Mac. Sci. Arts, XIII/2 (1992) 49.