2 From Niazi, S. 1979 `Textbook of Biopharmaceutics and Clinical Pharmacokinetics', Appleton- Century- Crofts, New York, NY, Fig 7.14 page 181
3 From Tozer, T.N. and Winter, M.E. 1980 Chapter 9, "Phenytoin" in `Applied Pharmacokinetics', Evans, W.E., Schentag, J.J., and Jusko, W.J. ed., Applied Therapeutics, San Francisco, CA Figure 11, page 302.