2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/54805This talk is a brief review of gaugino condensation in superstring effective field theories and some related issues (such as renormalization of the gauge coupling in the effective supergravity theories and modular anomaly cancellation). As a specific example, we discuss a model containing perturbative (1-loop) corrections to the Kähler potential and approximate S-duality symmetry.11 pages, LaTeX, One figure included; To appear in the proceedings of NATO ASI on Masses of Fundamental Particles, Càrgese, France, Aug. 5-17, 1996High Energy Physics - Theorytext