L. Li, G. Meller, H. Kosina:
"Analytical Conductivity Model for Doped Organic Semiconductors";
Journal of Applied Physics, 101 (2007), 033716; 1 - 4.
http://dx.doi.org/10.1063/1.2472282Electronic version of the publication:
http://www.iue.tuwien.ac.at/pdf/ib_2007/JB2007_Li_1.pdf