1. Existence of steady vortex rings in an ideal fluid;Ambrosetti;Arch. Rational Mech.,1989
2. The uniqueness of Hill's spherical vortex;Amick;Arch. Rational Mech.,1986
3. Nonlinear desingularization in certain free-boundary problems;Berger;Comm. Math. Phys.,1980
4. R. Courant, D. Hilbert, Methods of Mathematical Physics, Vol. II, Interscience, New York, 1966, pp. 369–374.
5. Equilibrium configurations of point vortices for channel flows past interior obstacles;Elcrat;European J. Mech.,1997