Adimurthi, Pacella, F., and Yadava, S.L., Characterization of concentration points and estimates for solutions of a semilinear Neumann problem involving the critical Sobolev exponent, Differential Integral Equations, 8, 41–68, 1995.
 Allendoerfer, C. B., The Euler number of a Riemann manifold, Amer. J.Math., 62, 243–248, 1940
 Allendoerfer, C. B., and Weil, A., The Gauss-Bonnet theorem for Riemannian polyhedra, Trans. Amer. Math. Soc., 53, 101–129, 1943
 Ambrosetti, A., and Rabinowitz, P. H., Dual variational methods in critical point theory and applications, J. Funct. Anal., 14, 349–381, 1973
 Atkinson, F. V., and ...