The Singular, Second Order Oblique Derivative Problem

Estimates near the boundary for solutions of elliptic partial differential equations satisfying general boundary conditions. I

Shmuel Agmon, Avron Douglis, Louis Nirenberg · Communications on Pure and Applied Mathematics · 1959 · 3.8K citations

Natural Sciences, Mechanical Engineering, Differential Equations +10

Pseudo-differential Operators and Non-elliptic Boundary Problems

Lars Hörmander · Annals of Mathematics · 1966 · 496 citations

Natural Sciences, Mathematics, Physics +13

Remarks on strongly elliptic partial differential equations

Louis Nirenberg · Communications on Pure and Applied Mathematics · 1955 · 399 citations

Natural Sciences, Mathematics, Differential Equations +10

On the theory of general partial differential operators

Lars Hörmander · Acta Mathematica · 1955 · 336 citations · Full text

Natural Sciences, Mathematics, Differential Equations +11

General boundary value problems for elliptic partial differential equations

Martin Schechter · Communications on Pure and Applied Mathematics · 1959 · 143 citations · Full text

Natural Sciences, Physics, Computational Mechanics +13