[en] To establish the Higgs mechanism sui generis experimentally, the Higgs self-interaction potential must be reconstructed. This task requires the measurement of the trilinear and quadrilinear self-couplings, as predicted in the standard model or in supersymmetric theories. The couplings can be probed in multiple Higgs production at high-luminosity e⁺e^- linear colliders. We present the theoretical analysis for the production of neutral Higgs-boson pairs in the relevant channels of double Higgs-strahlung and associated multiple Higgs production. (orig.)