1. Sur les périodes des solutiones de l'équation différentielle x″ + g(x) = 0;Opial;Annls pol. math.,1961
2. On an elementary phase plane analysis for solving second order BVP's;Fernandes;Rc. Mat.,1988
3. Global solution branches of two point boundary value problems;Schaaf,1987
4. A homotopic deformation along p of a Leray–Schauder degree result and existence for (¦u′¦ p−2u′)′ + f(t, u) = 0, u(0) = u(T) = 0, p > 1;Del Pino;J. diff. Eqns,1989
5. On the solvability of a semilinear two point BVP around the first eigenvalue;Fernandes;Diff. Integral Eqns,1989