On Electromagnetic Duality in Locally Supersymmetric N=2 Yang--Mills   Theory
  We consider duality transformations in N=2 Yang--Mills theory coupled to N=2 supergravity, in a manifestly symplectic and coordinate covariant setting. We give the essential of the geometrical framework which allows one to discuss stringy classical and quantum monodromies, the form of the spectrum of BPS saturated states and the Picard--Fuchs identities encoded in the special geometry of N=2 supergravity theories. 
A. Ceresole, R. D'Auria, S. Ferrara and A. Van Proeyen