Schwartz, S. E.; Warneck, P. (1995). Units for use in atmospheric chemistry (IUPAC Recommendations 1995). 67. IUPAC. 1377-1406. doi:10.1351/pac199567081377
Foreword NIST Handbook 44,2017 "In accord with NIST policy, the meter/liter spellings are used in this document. However, the metre/litre spellings are acceptable, and are preferred by the NCWM."