See also: O. Lishilin, D. Kalantaryan, D. Melkumyan, T. Rublack, X. Li, H. Qian, M. Krasilnikov, I. Isaev, Y. Renier, Ja.D. Good, P. Boonpornprasert, E.A. Khazanov, H. Huck, Y.L. Chen, F. Stephan
PACS: 29.20.-c, 29.27.Ac, 42.60.By, 42.60.-v