1. F. Riehle, Frequency Standards. Basics and Applications (Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, 2004), ISBN 3-527-40230-6
2. V.I. Chizhik, Y.S. Chernyshev, A.V. Donets, V.V. Frolov, A.V. Komolkin, M.G. Shelyapina, Magnetic Resonance and Its Applications (Springer-Verlag, 2014). https://doi.org/10.1007/978-3-319-05299-1
3. T. McClelland, T. Pascaru, I. Shtaermann, I. Varuolo, C. Szekeley, C. Zacharski, J. Bravo, Y. White, D.
Wilson, in Proceedings of the 43nd Annual Precise Time (PTTI) Systems and Applications Meeting (Long Beach, California, USA, 14–17 November 2011), pp. 325–340
4. A. Risley, S. Jarvis, J. Vanier, J. Appl. Phys. 51(9), 4571–4576 (1980)
5. Sh.Sh. Dolginov, A.N. Kozlov, M.M. Chinchevoi, Rev. Phys. Appl. 5(1), 178–182 (1970)