1. W. Biltz, Z. Anorg. Chem., 130 (1923) 93.
2. W. Biltz andH. G. Grimm, Z. Anorg. Chem., 145 (1925) 63.
3. N. Paravano andG. Malquori, Gazz. chim. ital. 56 (1926) 23.
4. G. B. Seifer, Ż. nieorg. chim., 7 (1962) 482, 1208, 1242, 1746, 2290.
5. C. Duval, Inorganic thermogravimetric analysis, Elsevier Publishing Company. Amsterdam 1953.