H. Schmidt, M. Diaconu, H. Hochmuth, M. Lorenz, A. Setzer, P. Esquinazi, A. Poppl, D. Spemann, KW. Nielsen, R. Gross, G. Wagner, M. Grundmann: Weak ferromagnetism in textured Zn1-x(TM)(x)O thin films. 2006Superlattices and Microstructures: 39. ISBN 0749-6036 http://dx.doi.org/10.1016/j.spmi.2005.08.059