Variational method for the nonlinear dynamics of an elliptic magnetic stagnation line A. H. Khater, D. K. Callebaut, M. A. Helal and A. R. Seadawy Eur. Phys. J. D, 39 2 (2006) 237-245 Published online: 28 April 2006 DOI: 10.1140/epjd/e2006-00093-3