2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/35755Four--dimensional Einstein--Maxwell--dilaton--axion system restricted to space--times with one non--null Killing symmetry is formulated as the three--dimensional gravity coupled sigma--model. Several alternative representations are discussed and the associated hidden symmetries are revealed. The action of target space isometries on the initial set of (non--dualized ) variables is found. New mulicenter solutions are obtained via generating technique based on the formulation in terms of the non--dualized variables.Talk at the Dubna Workshop ``Geometry and Integrable models'', JINR, Dubna, (Russia), October 1994 , published in the Proceedings, ``Geometry and Integrable models'', P.N. Pyatov and S.N. Solodukhin (Eds.), World Scientific, 1996General Relativity and Quantum CosmologyHigh Energy Physics - Theorytext