Index theory for skew-adjoint Fredholm operators Michael F. Atiyah; Isadore M. Singer — 1969 Publications Mathématiques de l'IHÉS
C * -algebras of operators on a half-space, II. Index theory Lewis A. Coburn; Ronald G. Douglas; David G. Schaeffer; Isadore M. Singer — 1971 Publications Mathématiques de l'IHÉS
The index of projective families of elliptic operators. Mathai, Varghese; Melrose, Richard B.; Singer, Isadore M. — 2005 Geometry & Topology