Multi-step preconditioned iteration method for nonsymmetric linear systems. - Toshiyuki Kohno; Hiroshi Niki; Masataka Usui (Int. J. Comput. Math., 1995)

On the preconditioned sor method. - Masataka Usui; Toshiyuki Kohno; Hiroshi Niki (Int. J. Comput. Math., 1995)

An extension of the criteria for generalized diagonally dominant matrices. - Masunori Harada; Mastaka Usui; Hiroshi Niki (Int. J. Comput. Math., 1996)