TY  - RPRT
TI  - Reference materials--a main element in a coherent reference measurement system.
AU  - R Dybkaer
PY  - 1991
DO  - 10.1515/cclm.1991.29.4.241
UR  - https://pubmed.ncbi.nlm.nih.gov/1868129/
ID  - 1868129
ER  -