1. [1] R.A. Adams, Sobolev Spaces, Academic Press, New York, 1975.
2. [2] G. Alefeld and J. Herzberger, Introduction to Interval Computations, Academic Press, New York, 1993.
3. The Cholesky method for interval data
4. [4] P.G. Ciarlet, The Finite Element Method for Elliptic Problems, North-Holland, Amsterdam, 1978.
5. [5] P. Grisvard, Elliptic Problems in Nonsmooth Domains, Pitman, Boston, 1985.