1. 1) R. Blachnik, R. Igel and P. Wallbrecht: Z. Naturfosch., 29 (1974), 1198.
2. 2) C. H. Shomate: J. Phys. Chem., 58 (1954), 368.
3. 3) J. Koh and K. Itagaki: Bull. Res. Inst. Miner. Dress. and Metall., Tohoku Univ., 36 (1983), 37.
4. 4) O. Knacke, O. Kubaschewski and K. Hesselmann: Thermochemical Properties of Inorganic Substances, Springer-Verlag, Berlin, Heidelberg, (1991), p. 47, 421, 425, 1572, 1574, 1894, 1900, 1903, 2353, 2356.
5. 5) K. Itagaki and K. Yamaguchi: Thermochim. Acta, 163 (1990), 1.