@article{escidoc:0617, title = {{Magnetic ground states and the role of vortices in ferromagnetic hollow nanospheres}}, author = {Goll, D. and Macke, S. and Berkowitz, A.E. and Bertram, H. N.}, journal = {{Physica B: Condensed Matter}}, volume = {372}, number = {1-2}, pages = {282--285}, year = {2006}, doi = {} }