For an "upgraded" version of the correspondence see the newly appeared M.Bunge, J. Funk, M. Jibladze, T. Streicher "Distribution Algebras and Duality" Advances in Mathematics 156, 133-155 (2000) This is done for a bounded topos E--->S, replacing S = Coc_S(S,S) by Dist(E) = Coc_S(E,S) and caBA(S) by "distribution algebras". Identifying E with S gives the correspondence in question. For just that one, it may be worthwhile to consult directly Mikkelsen's thesis combined with Pare's Theorem. Marta Bunge