RT null T1 Bi-ennial Global Interlaboratory Assessment on Persistent Organic Pollutants – Fourth Round 2018 A2 van der Veen, Ike A2 Fiedler, Heidelore A2 de Boer, Jacob K1 persistent organic pollutant YR 2018 FD 2018 LK https://wedocs.unep.org/handle/20.500.11822/26111 UL https://wedocs.unep.org/handle/20.500.11822/26111 DS UN Environment Document Repository RD Sep 19, 2026