1. Sobolev Spaces;Adams,1975
2. A Posteriori Error Estimation in Finite Element Analysis;Ainsworth,2000
3. Introduction to Interval Computations;Alefeld,1983
4. The Finite Element Method and its Reliability;Babuška,2001
5. I. Babuška, O.C. Zienkiewicz, J. Gago, E.R. de A. Oliveira (Eds.), Accuracy Estimates and Adaptive Refinements in Finite Element Computation, Wiley, New York, 1986.