Vysekantsev, I.P., Martsenyuk, V.F., Kudokotseva, E.V., Koschiy, S.V. and Petrenko, T.F. 2005. Experience of storage of asporogenic anaerobic bacteria at liquid nitrogen temperature. Problems of Cryobiology and Cryomedicine. 15, 3 (Sep. 2005), 263–266.