(1) Stephanie Bell, National Physical Laboratory
"Measurement Good Practice Guide No. 11 - A Beginner's Guide to Uncertainty of Measurement"
S. A. Bell, ISSN 1368-6550
http://www.npl.co.uk/people/stephanie-bell
(1) BIPM, IEC, IFCC, ISO, IUPAC, IUPAP, OIML.
"Guide to the Expression of Uncertainty in Measurement"
International Organisation for Standardization, Geneva, Switzerland. ISBN 92-67-10188-9, First Edition 1993.
http://www.bipm.org/utils/common/documents/jcgm/JCGM_100_2008_E.pdf