M Fernandes-Whaley, D Prevoo-Franzsen, L Quinn, N Nhlapo. How well do our measurements measure up? An overview of South Africa’s first proficiency testing scheme for organochlorine pesticides in water. WSA [Internet]. 2015 Mar. 31 [cited 2024 May 3];41(2 WISA 2014 Special Edition). Available from: https://watersa.net/article/view/11073