2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/210295Sturm theory for second order differential equations was generalized to systems and higher order equations with positive leading coefficient by several authors. Here we propose a Sturm oscillation theorem for indefinite systems of even order and with Dirichlet boundary conditions having strongly indefinite leading term.3 pagesClassical Analysis and ODEstext