1. Diem, M.: Messungen der Größe von Wolkenelementen, II. Meteorol. Rundschau1, 261–273 (1948).
2. Elster, J., und H. Geitel: Zur Influenztheorie der Niederschlagselektrizität. Physik. Z.14, 1287–1292 (1913).
3. Frenkel, J.: Atmospheric Electricity and Lightning. J. Franklin Inst.243, 287 (1947).
4. Gott, J. P.: On the Electric Charge Collected by Water Drops Falling through a Cloud of Electrically Charged Particles in a Vertical Electric Field. Proc. Roy. Soc., A,142, 248–268 (1933).
5. Gott, J. P.: On the Electric Charge Collected by Water Drops Falling through a Cloud of Electrically Charged Particles in a Vertical Electric Field. Proc. Roy. Soc., A,151, 665–684 (1935).