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Tennyson, Jonathan(March 2013).”IUPAC critical evaluation of the rotational–vibrational spectra of water vapor, Part III: Energy levels and transition wavenumbers for H216O”.Journal of Quantitative Spectroscopy and Radiative Transfer117: sid.29–58. doi:10.1016/j.jqsrt.2012.10.002. Bibcode:2013JQSRT.117...29T.
Gordon, J. P.; Zeiger, H. J.; Townes, C. H.(1955).”The Maser—New Type of Microwave Amplifier, Frequency Standard, and Spectrometer”.Phys. Rev.99(4): sid.1264. doi:10.1103/PhysRev.99.1264. Bibcode:1955PhRv...99.1264G.
Tennyson, Jonathan(March 2013).”IUPAC critical evaluation of the rotational–vibrational spectra of water vapor, Part III: Energy levels and transition wavenumbers for H216O”.Journal of Quantitative Spectroscopy and Radiative Transfer117: sid.29–58. doi:10.1016/j.jqsrt.2012.10.002. Bibcode:2013JQSRT.117...29T.