Analytical Reference Materials International http://www.armi.com/
ASTM; International - Standards Worldwide http://www.astm.org/cgi-bin/SoftCart.exe/index.shtml?E+mystore
BAM (German) http://www.bam.de/
Brammer Standard http://www.brammerstandard.com/default.htm
CEN - European Committee for Standardization http://www.cen.eu/cenorm/homepage.htm
Chemical Metrology - Client Services | NRC-INMS http://inms-ienm.nrc-cnrc.gc.ca/calserv/chemical_metrology_e.html#Certified
COMAR Database for Certified Reference Materials http://www.comar.bam.de/
Institute for National Measurement Standards http://inms-ienm.nrc-cnrc.gc.ca/
Institute for Reference Materials and Measurements http://www.irmm.jrc.be/html/reference_materials_catalogue/catalogue/index.htm
International Association of Geoanalysts http://geoanalyst.org/
International Center for Diffraction Data https://www.dxcicdd.com/
International Organization for Standardization http://www.iso.org/iso/home.htm
NIST: National Institute of Standards and Technology http://ts.nist.gov/measurementservices/referencematerials/index.cfm