- ISO 1:2002 - Geometrical Product Specifications (GPS) - Standard reference temperature for geometrical product specification and verification. Iso.org. 2008-01-23 [2012-06-20].
- Ted Doiron: 20 °C—A Short History of the Standard Reference Temperature for Industrial Dimensional Measurements. Journal of Research of the National Institute of Standards and Technology, Vol. 112, No. 1, January–February 2007.