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 Transfer 117: sid. 29–58. doi:10.1016/j.jqsrt.2012.10.002. Bibcode: 2013JQSRT.117...29T.
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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.
Neufeld, David A.; Melnick, Gary J. (1991). ”Excitation of Millimeter and Submillimeter Water Masers in Warm Astrophysical Gas”. Atoms, Ions and Molecules: New Results in Spectral Line Astrophysics, ASP Conference Series (ASP: San Francisco) 16: sid. 163. Bibcode: 1991ASPC...16..163N.
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 Transfer 117: sid. 29–58. doi:10.1016/j.jqsrt.2012.10.002. Bibcode: 2013JQSRT.117...29T.