H. M. Goldenberg, D. Kleppner, and N. F. Ramsey, "Atomic hydrogen maser, " Phys. Rev. Lett., vol. 5, pp. 361-362, 1960.
D. Kleppner, H. M. Goldenberg, and N. F. Ramsey, "Theory of the hydrogen maser, " Phys. Rev., vol. 126, pp. 603-615, 1962.
D. Kleppner, H. C. Berg, S. B. Crampton, et al., "Hydrogen maser principles and techniques, " Phys. Rev. A, vol. 138, pp. 972-983, 1965.
J. Vanier and C. Audoin, The Quantum Physics of Atomic Frequency Standards. Bristol: Hilger, 1989.
A. T. Hjartarson, E. G. Thorsteinsson, and J. T. Gudmundsson, "Low pressure hydrogen discharges diluted with argon explored using a global model, " Plasma Sources Sci. Technol., vol. 19, 065008: 1-15, 2010.
C. M. Samuell and C. S. Corr, "Low-pressure hydrogen plasmas explored using a global model, " Plasma Sources Sci. Technol., vol. 25, 015014: 1-15, 2016.
M. Sode, T. Schwarz-Selinger, W. Jacob, and H. Kersten, "Surface loss probability of atomic hydrogen for different electrode cover materials investigated in h2-ar lowpressure plasmas, " J. Appl. Phys., vol. 116, 013302: 1-10, 2014.
R. Zorat, "Numerical modelling of low temperature radio-frequency hydrogen plasmas, " Ph. D. dissertation, Dublin, 2003.
J.-J. Dang, K.-J. Chung, and Y. S. Hwang, "A simple spectroscopic method to determine the degree of dissociation in hydrogen plasmas with wide-range spectrometer, " Rev. Scient. Instrum., vol. 87, 053503: 1-6, 2016.
