See also: X. Leyronas, M.Yu. Kagan, I.V. Brodskii, A.V. Klaptsov, M.N. Chizhkov, V.A. Cherepenin, A.K. Murtazaev, V.Yu. Politov, V.A. Lykov, P.A. Loboda, A.V. Andriyash
PACS: 03.75.Mn, 21.45.+v, 32.80.Pj