Saffman, P.G. (1971) On the Boundary Condition at the Surface of a Porous Medium. Studies in Applied Mathematics, 50, 93-101.
http://dx.doi.org/10.1002/sapm197150293

has been cited by the following article:

• TITLE: Flow over a Darcy Porous Layer of Variable Permeability

  AUTHORS: M. S. Abu Zaytoon, T. L. Alderson, M. H. Hamdan

  KEYWORDS: Coupled-Parallel Flow, Darcy Equation, Variable Permeability

  JOURNAL NAME: Journal of Applied Mathematics and Physics, Vol.4 No.1, January 25, 2016

  ABSTRACT: In this work we consider coupled-parallel flow through a finite channel bounded below by a porous layer that is either finite or infinite in depth. The porous layer is one in which Darcy’s equation is valid under the assumption of variable permeability. A suitable permeability stratification function is derived in this work and the resulting variable velocity profile is analyzed. It will be shown that when an infinite porous layer is implemented, Darcy’s equation must be used with a constant permeability.