2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/101258We classify all the possible configurations of singular fibers and the torsion parts of Mordell-Weil groups of complex elliptic K3 surfaces. The complete list of 3279 configurations is attached.110 pages, with a table; Lemma 5.2 and minor typos are corrected, some references are updated, the table is not changedAlgebraic Geometry14J28text