1. These references are listed in reference 1.
2. L. Spitzer, Jr.,Physics of Fully Ionized Gases(Interscience Publishers, Inc., New York, 1956), p. 76.
3. Note added in proof. Actually these preceding arguments show that the conductivity perpendicular to the magnetic field does not require the first of these restrictions, ωtD≫1. Indeed, if one examines the result, Eq. (52), in the limit ω≪ωo≪ωp, one obtains Spitzer’s result (reference 4, p. 86) for the dc conductivity perpendicular to a large magnetic field.