Isoperimetric and Sobolev inequalities for Carnot-Carath�odory spaces and the existence of minimal surfaces

Hypoelliptic second order differential equations

Lars Hörmander · Acta Mathematica · 1967 · 2.4K citations · Full text

Oscillation Theory, Nonlinear Hyperbolic Problem, Nonlinear Equation

Hypoelliptic differential operators and nilpotent groups

Linda Preiss Rothschild, E. M. Stein · Acta Mathematica · 1976 · 1.1K citations · Full text

Lie Group, Nilpotent Group, Hypoelliptic Differential Operators +1

Estimates for the \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop \partial \limits^ - _b $\end{document} complex and analysis on the heisenberg group

Gerald B. Folland, E. M. Stein · Communications on Pure and Applied Mathematics · 1974 · 955 citations

Spectral Theory, Engineering, \Mathop \Partial \Limits^ +2

Balls and metrics defined by vector fields I: Basic properties

Alexander Nagel, Elias M. Stein, Stephen Wainger · Acta Mathematica · 1985 · 881 citations · Full text

Integral Geometry, Global Geometry, Engineering +5

Sub-Riemannian geometry

Robert S. Strichartz · Journal of Differential Geometry · 1986 · 650 citations · Full text