2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/54398A few observations concerning topological string theories at the string-tree level are presented: (1) The tree-level, large phase space solution of an arbitrary model is expressed in terms of a variational problem, with an ``action'' equal, at the solution, to the one-point function of the puncture operator, and found by solving equations of Gauss-Manin type; (2) For $A_k$ Landau-Ginzburg models, an extension to large phase space of the usual residue formula for three-point functions is given.LaTeX2e, 8 pagesHigh Energy Physics - Theorytext