2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/45333I review recent determinations of the (on-shell) charm- and beauty-quark masses in the framework of relativistic and non-relativistic ratios of Laplace transform QCD moment sum rules. The validity of the non-relativistic version of QCD sum rules in this particular application is discussed.Invited talk at the Mexican School of Particles and Fields, Villahermosa, Mexico, October 1994. 5 pages. LATEX file. UCT-TP-219/94High Energy Physics - Phenomenologytext