*Physical and Biophysical Chemistry Division Commission on Molecular Structure and Spectroscopy, Recommendations for nomenclature and symbolism for mass spectroscopy (including an appendix of terms used in vacuum technology). (Recommendations 1991), Pure and Applied Chemistry, 1991, Vol. 63, No. 10, pp. 1541-1566 doi:10.1351/pac199163101541
iupac.org
goldbook.iupac.org
IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "atomic mass".