The correlation of fractal structures in the photospheric and the coronal magnetic field M. Dimitropoulou, M. Georgoulis, H. Isliker, L. Vlahos, A. Anastasiadis, D. Strintzi and X. Moussas A&A, 505 3 (2009) 1245-1253 Published online: 18 August 2009 DOI: 10.1051/0004-6361/200911852