See also: X. Li, I. Isaev, O. Lishilin, T. Rublack, H. Qian, M. Krasilnikov, D. Kalantaryan, Ja.D. Good, Y. Renier, M. Gross, 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