2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/49672I review the theoretical progress made in these 4 years concerning the process e+e- -> ttbar in the threshold region. I summarize the progress towards each of the three major physics goals that should be achieved at ttbar threshold region.Talk given at the International Workshop on Linear Colliders, April 28 - May 5, 1999, Sitges, SpainHigh Energy Physics - Phenomenologytext