2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/94402The correspondance is established between the sigma models, the minimal surfaces and the Monge-Ampere equation. The Lax -Pairs of the minimality condition of the minimal surfaces and the Monge-Ampere equations are given. Existance of infinitely many nonlocal conservation laws is shown and some Backlund transformations are also given.Latex, 13pp, to be published in Letters in Mathematical PhysicsExactly Solvable and Integrable Systemstext