by Litvintsev, V. V., Bukin, V. A., Didovich, Yu. N.
Published in Soviet Physics Journal (01.04.1976)

by Glukhov, Yu. B., Didovich, Yu. N., Litvintsev, V. V.
Published in Soviet Physics Journal (01.09.1975)

by Buravikhin, V. A., Litvintsev, V. V., Didovich, Yu. N., Kazakov, V. G., Ushakov, A. I.
Published in Czechoslovak journal of physics (01.01.1974)