Switching of vortex polarization in 2D easy-plane magnets by magnetic fieldsJ. P. Zagorodny, Y. Gaididei, F. G. Mertens and A. R. BishopEur. Phys. J. B, 31 4 (2003) 471-487DOI: https://doi.org/10.1140/epjb/e2003-00057-y