Bethe-Salpeter equation with cross-ladder kernel in Minkowski and   Euclidean spaces
  Some results obtained by a new method for solving the Bethe-Salpeter equation are presented. The method is valid for any kernel given by irreducible Feynman graphs. The Bethe-Salpeter amplitude, both in Minkowski and in Euclidean spaces, and the binding energy for ladder + cross-ladder kernel are found. We calculate also the corresponding electromagnetic form factor. 
V.A. Karmanov, J. Carbonell and M. Mangin-Brinet