@misc{101486, author = {Dean Ripple and Anatoly Pokhodun and Peter Steur and Gregory Strouse}, title = {Recommended List of Common Impurities for Metallic Fixed-point Materials of the ITS-90}, year = {2008}, month = {2008-08-18}, publisher = {website of the International Bureau of Weights and Measures}, url = {https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=832299}, language = {en}, }