2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/9675The Lagrangian theory of gravitational instability of homogeneous-isotropic Friedman-Lemaitre cosmogonies investigated and solved in the series of papers by Buchert (1989), (1992), Buchert & Ehlers (1993), Buchert (1993a,b), Ehlers & Buchert (1993), is illustrated. The third-order solution of this theory for generic initial conditions is presented and realized in a special case by employing methods of high-spatial resolution of the density field.uuencoded compressed postscript file to appear in: Proc of IAP Colloq. 9, ``Cosmological velocity fields'', ed. F.Bouchet, M.Lachieze-Rey Dummy report number MPA-000-000-93Astrophysicstext