1. US Patent 4268326.
2. US Patent 4255205
3. US Patent 3930906.
4. Grigorovich, K.V., Anal. Kontr., 2000, vol. 4, no. 3, pp. 244–251.
5. Grigorovich, K.V., Krasovskii, P.V., Isakov, S.A., Gorokhov, A.A., and Krylov, A.S., Zavod. Lab. Diagn. Mater., 2002, vol. 68, no. 9, pp. 3–9.