The Porous Medium Equation: Mathematical Theory. : Oxford University Press, 2006-10-26. Oxford Scholarship Online. 2007-09-01. Date Accessed 22 May. 2013 <http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780198569039.001.0001/acprof-9780198569039>.
(2006-10-26). The Porous Medium Equation: Mathematical Theory. : Oxford University Press. Retrieved 22 May. 2013, from http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780198569039.001.0001/acprof-9780198569039.
The Porous Medium Equation: Mathematical Theory. : Oxford University Press, 2006-10-26. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780198569039.001.0001/acprof-9780198569039.
Vazquez JL. The Porous Medium Equation: Mathematical Theory. Oxford University Press; 2006. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780198569039.001.0001/acprof-9780198569039. Accessed May 22, 2013.