1. Nonlinear elliptic boundary value problems;Browder, Felix E.;Bull. Amer. Math. Soc.,1963
2. On the geometry of function spaces;Eells, James, Jr.,1958
3. Existence and differentiability theorems for variational problems for multiple integrals;Morrey, Charles B., Jr.,1961
4. Multiple integral problems in the calculus of variations and related topics;Morrey, Charles B., Jr.;Ann. Scuola Norm. Sup. Pisa Cl. Sci. (3),1960