1. 3)BIPM, IEC, IFCC, ISO, IUPAC, IUPAP, OIML: International vocabulary of basic and general terms in metrology, Second edition, ISO (1993)
2. 4)BIPM, IEC, IFCC, ISO, IUPAC, IUPAP, OIML: Guide to the expression of uncertainly in measurement, First edition, ISO (1993)