Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) Matschat Ralf and Czerwensky Michael and Pattberg Sandra and Heinrich Hans-Joachim and Tutschku Silke,High Purity Metals as Primary Calibration Materials for Elemental Analysis-Their Importance and Their Certification,MATERIALS TRANSACTIONS,13459678,The Japan Institute of Metals and Materials,2002,43,2,90-97,https://cir.nii.ac.jp/crid/1390282679225129344,https://doi.org/10.2320/matertrans.43.90