1. A. Knop and W. Scheib, Chemistry and Application of Phenolic Resins (Springer, Heidelberg, 1979; Khimiya, Moscow, 1983).
2. V. I. Bukin, A. M. Reznik, and S. A. Semenov, Fundamental Problems od Russian Metallurgy on the Verge of the 21st Century, vol. 3: Metallurgy of Rare and Scattered Elements, Ed. by D. V. Drobot (RAEN, Moscow, 1999) [in Russian].
3. S. A. Semenov, A. Yu. Matviets, and A. M. Reznik, Zh. Neorg. Khim. 53(6), 1040 (2008) [Russ. J. Inorg. Chem. 53 (6), 965 (2008)].
4. N. Adler and C. F. Hiskey, J. Am. Soc. 79, 1827 (1957).
5. N. Adler and C. F. Hiskey, J. Am. Soc. 79, 1831 (1957).