1. Berestycki, H., Caffarelli, L., Nirenberg, L.: Symmetry for elliptic equations in a half space. In: Boundary Value Problems for Partial Differential Equations and Applications. Research Notes in Applied Mathematics, vol. 29, pp. 27–42, Masson (1993)
2. Berestycki, H., Caffarelli, L.A., Nirenberg, L.: Inequalities for second-order elliptic equations with applications to unbounded domains I. A celebration of John F. Nash Jr. Duke Math. J. 81, 467–494 (1996)
3. Berestycki, H., Caffarelli, L.A., Nirenberg, L.: Further qualitative properties for elliptic equations in unbounded domains, Dedicated to Ennio De Giorgi. Ann. Scuola Norm. Sup. Pisa Cl. Sci. 25, 69–94 (1997)
4. Berestycki, H., Nirenberg, L.: Monotonicity, symmetry and antisymmetry of solutions of semilinear elliptic equations. J. Geom. Phys. 5, 237–275 (1988)
5. Berestycki, H., Nirenberg, L.: Some qualitative properties of solutions of semilinear elliptic equations in cylindrical domains. In: Analysis, et Cetera, pp. 115–164. Academic Press, Boston (1990)