1. J. J. Thomsox: Conduction of Electricity through Gases, 2nd edit. Cambridge 1906.
2. J. J. and G. P. Thomson: Conduction of Electricity through Gases, 3rd edit. Cambridge 1933.
3. J. S. Townsend: Marx’s Handbuch der Radiologie, Bd. 1. Leipzig: Akademische Verlagsgesellschaft 1916.
4. J. S. Townsend: Electricity in Gases. Oxford: Clarendon Press 1915.
5. J. S. Townsend: Theory of Ionization of Gases by Collision. London: Constable 1910.