Periodic instantons and domain structure in a ferromagnetic film G.-P. Zheng, J.-Q. Liang, Y.-H. Nie and W. Yin Eur. Phys. J. B, 36 2 (2003) 215-220 Published online: 08 December 2003 DOI: 10.1140/epjb/e2003-00338-5