Secondary Circulation in Granular Flow Through Nonaxisymmetric Hoppers. - David G. Schaeffer; John V. Matthews; Pierre-Alain Gremaud (SIAM J. Appl. Math., 2004)

A Well-Posed Free Boundary Value Problem for a Hyperbolic Equation with Dirichlet Boundary Conditions. - John V. Matthews; David G. Schaeffer (SIAM J. Math. Anal., 2004)

On the computation of steady hopper flows III: Model comparisons. - Pierre-Alain Gremaud; John V. Matthews; David G. Schaeffer (J. Comput. Phys., 2006)