F. Sanz, NONOSCILLATING SOLUTIONS OF GRADIENT VECTOR-FIELDS, Comptes rendus de l'Academie des sciences. Serie 1, Mathematique, 325(4), 1997, pp. 429-432
Let f be a germ of order 2 of an analytic function at the origin in R-
3. Let gamma be a solution of the gradient of f with respect to some a
nalytic Riemannian metric. Then, for ail germs of analytic surface H,
either gamma subset of H, or gamma cuts H finitely many times.