1. Whittaker, E.: History of the theories of aether and electricity, (Nelson 1951),1, p. 33–34
2. Whittaker, E.: History of the theories of aether and electricity, (Nelson 1951),1, p. 56–57
3. Maxwell, J.C.: Electricity and magnetism, 3rd edn(Clarendon Press 1892),2, sections 553-584