Landau, L.D.; On the Energy Loss of Fast Particles by Ionization
Jour. Phys. USSR 8, 201 (1944);
(translation into English) Collected Papers of L. D. Landau ed. D. Ter Haar, Gordon and Breach, Science Publishers, London (1965) 417.
The energy distribution function has been determined for fast particles which have traversed a layer of matter of a given thickness and lost energy in the latter as a result of ionization collisions.
Related references See also L. Livingston and H. A. Bethe, Rev. of Mod. Phys. 9 (1937) 245;
Landau distribution for fast particle energy loss by ionization.