1. Tokyo sokki kenkyujo strain gages (2010).
https://www.tml.jp/e/download/catalog/STRAIN_GAUGES.pdf
2. Zhonhhang electronic measuring instruments (2010).
http://www.zemiceurope.com/media/Straingagescatalogue.pdf
3. (2014)
http://www.ni.com/white-paper/3642/en/
4. (2014)
http://www.ni.com/white-paper/4176/en/
5. Strain gauges: absolute precision from HBM (HBM strain gauge catalogue) (2014). Available on-line at
http://www.hbm.com/fileadmin/mediapool/hbmdoc/technical/s1265.pdf