Manuel Prieto R. Santiago David Espadas Ignacio Martín Llorente Francisco Tirado Parallel Multigrid for Anisotropic Elliptic Equations. 96-114 2001 61 J. Parallel Distrib. Comput. 1 http://dx.doi.org/10.1006/jpdc.2000.1666 db/journals/jpdc/jpdc61.html#PrietoSELT01