O. Axelsson and L. Yu. Kolotilina.International Conference on Preconditioned Conjugate Cradient Methods(1989 : Univ. of Nijmegen)：Preconditioned conjugate gradient methods; proceedings of a conference, Nijmegen, 1989.Springer-Verlag,1990.
International Conference on Preconditioned Conjugate Cradient Methods(1989 : Univ. of Nijmegen)：Preconditioned conjugate gradient methods; proceedings of a conference, Nijmegen, 1989
O. Axelsson and L. Yu. Kolotilina.Springer-Verlag,1990.
