1. Sobolev Spaces, Academic Press, New York, 1975.
2. Lectures on Elliptic Boundary Value Problems, van Nostrand, New York, 1965.
3. “Existence theorems in elasticity, and Unilateral constraints in elasticity”, Handbuch der physik, VIa/2, Springer, Berlin 1972, pp. 347-424.
4. Zur theorie elastischer schwingungen in inhomogenen medien