by Kolosov, V. Yu, Shvamm, K. L., Gainutdinov, R. V., Tolstikhina, A. L.
Published in Bulletin of the Russian Academy of Sciences. Physics (01.10.2007)

by Aksel’rod, E. G., Kuz’min, A. N., Kryuk, V. I., Dobrin, V. A., Shvamm, K. L.
Published in Technical physics letters (01.07.2001)