Description Abstract: I shall describe how one calculates the cross-section distribution for e+e- annihilation into Lambda-Lambdabar pairs. The reaction is assumed to proceed via vector-meson intermediate states, exemplified by the photon and the J/Psi meson. The hyperons are detected indirectly through their N-pi weak decays. Experiments of this kind are presently performed at BESIII where many physicists of our division are participating. I shall therefore try to make my presentation as clear and complete as possible.