Erhel J. Least-squares polynomial filters for ill-conditioned linear systems / J.Erhel,F.Guyomarch,Y.Saad, 2001. - 29 p. - Текст : непосредственный.
deflated version of the conjugate gradient algorithm / Y.Saad,M.Yeung,J.Erhel,F.Guyomarc'h, 1998. - 16 p. - Текст : непосредственный.