Homogeneity of infinite dimensional isoparametric submanifolds. Heintze, Ernst; Liu, Xiaobo — 1999 Annals of Mathematics. Second Series
Compact Quotients of Homogeneous Negatively Curved Riemannian Manifolds. Ernst Heintze — 1974 Mathematische Zeitschrift
Representations of Compact Lie Groups and Elliptic Operators. Ernst Heintze; Jochen Brüning Inventiones mathematicae
A general comparison theorem with applications to volume estimates for submanifolds Ernst Heintze; Hermann Karcher — 1978 Annales scientifiques de l'École Normale Supérieure