Bureau International des Poids et Mesures (BIPM): Guide to the expression of uncertainty in Measurement (GUM), 1st ed., JCGM 100 (2008)
S. Kim, J. Surek, J. Baker-Jarvis and V. Provenzano: Electromagnetic Properties of Iron Oxide Corrosion Product Powders at Radio Frequencies, CPEM2012 conference digests, 640/641 (2012)