Müller-Kirsten H. J. W. Electrodynamics: An Introduction Including Quantum Effects. — Singapore: World Scientific, 2004. — 522 p. — ISBN 981-238-807-9.
Müller-Kirsten H. J. W. Electrodynamics: An Introduction Including Quantum Effects. — Singapore: World Scientific, 2004. — P. 137-138. — 522 p. — ISBN 981-238-807-9.