Sixth Copper Mountain Conference on Multigrid Methods : proceedings of a workshop cosponsored by the National Aeronautics and Space Administration ... [et al.] and held at Copper Mountain, Colorado, April 4-9, 1993 / - Manteuffel, Thomas Albert,; McCormick, S. F.; Melson, N. Duane. (National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Program,, 1993)