@book{
international2011iaea,
title={Worldwide Proficiency Test: Determination of Minor and Trace Elements in Grass Mixture IAEA-PTXF-06},
series={Analytical Quality in Nuclear Applications Series},
number={20},
year={2011},
url={http://www.dgdingfa.net/publications/8487/worldwide-proficiency-test-determination-of-minor-and-trace-elements-in-grass-mixture-iaea-ptxf-06},
publisher={INTERNATIONAL ATOMIC ENERGY AGENCY},
address={Vienna}
}