1. Axelsson, O.: Conjugate gradient type methods for unsymmetric and inconsistent systems of linear equations, RR.78.03R, Department of Computer Sciences, Chalmers University of Technology, Göteborg, Sweden 1978
2. Axelsson, O.: Conjugate gradient type methods for unsymmetric and inconsistent systems of linear equations. Linear Algebra Appl.29, 1?16 (1980)
3. Lect. Notes Math.;O. Axelsson,1980
4. Axelsson, O., Barker, V.A.: Finite element solutions of boundary value problems. Theory and Computation. Orlando: Academic Press 1984
5. Axelsson, O., Lindskog, G.: On the rate of convergence of the conjugate gradient method. Numer. Math.48, 499?523 (1986)