@article{Nield_2008 author = {D. A. Nield}, title = {Effects of Combined Horizontal and Vertical Heterogeneity on the Onset of Transient Convection in a Porous Medium}, journal = {Journal of Porous Media}, issn = {1091-028X}, year = {2008}, volume = {11}, number = {4}, pages = {377--387} }