1. Savvin, S.B.,Dokl. Akad. Nauk SSSR, 1959, vol. 127, no. 6, p. 1231.
2. Savvin, S.B., USSR Inventor’s Certificate no. 20405,Byull. Izbret., 1959, no. 2.
3. Kuznetsov, V.I.,Dokl. Akad. Nauk SSSR, 1941, vol. 31, no. 9, p. 895.
4. Kuznetsov, V.I.,Zh. Anal. Khim., 1959, vol. 14, no. 1, p. 7.
5. Kuznetsov, V.I. and Savvin, S.B.,Zh. Prikl. Khim. (Leningrad), 1959, vol. 32, p. 2329.