1. Error-bounds for finite element method;Babuška, Ivo;Numer. Math.,1970
2. I. Babuška & A. Aziz, "Survey lectures on the mathematical foundations of the finite element method" in The Mathematical Foundations of the Finite Element Method with Application to Partial Differential Equations (A. K. Aziz, Ed.), Academic Press, New York, 1973, pp. 5-359.
3. Numerical treatment of eigenvalue problems for differential equations with discontinuous coefficients;Babuška, I.;Math. Comp.,1978
4. Rate of convergence estimates for nonselfadjoint eigenvalue approximations;Bramble, J. H.;Math. Comp.,1973
5. Analysis of mixed methods using mesh dependent norms;Babuška, I.;Math. Comp.,1980