2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/54540This paper surveys recent work on Lie algebras of differential operators and their application to the construction of quasi-exactly solvable Schroedinger operators.LaTex, 25 pages. Talk presented at the IV Workshop on Differential Geometry and its Applications (Santiago de Compostela, Spain, 18--20 September 1995)High Energy Physics - Theorytext