1. Vortex crystals;Aref;Adv. Appl. Math.,2003
2. S. Boatto, Curvature perturbations and stability of a ring of vortices, Discrete Continuous Dynam. Syst. (2007) (in press)
3. S. Boatto, C. Simó, Stability of latitudinal vortex rings with polar vortices, preprint, 2004. http://www.ma.utexas.edu/mp_arc/a/04-67
4. Stability of relative equilibria in the problem of N+1 vortices;Cabral;SIAM J. Math. Anal.,1999
5. G. Lejeune, Dirichlet, Werke, vol. 2, Berlin, pp. 5–8, 1897