M Fernandes-Whaley, et al. “How Well Do Our Measurements Measure Up? An Overview of South Africa’s First Proficiency Testing Scheme for Organochlorine Pesticides in Water”. Water SA, vol. 41, no. 2 WISA 2014 Special Edition, Mar. 2015, https://doi.org/10.4314/wsa.v41i2.01.