A description of the ratio between electric and magnetic proton form   factors by using space-like, time-like data and dispersion relations
  We use the available information on the ratio between the electric and magnetic proton form factors coming from recently published space-like data and from the few available time-like data. We apply a dispersive procedure on these data to evaluate the behaviour of this ratio, as a complex function, for all values of q^2. 
R. Baldini, C. Bini, P. Gauzzi, M. Mirazita, M. Negrini, S. Pacetti