Rouchaud, J., Moons, C., Benoit, F., Ceustermans, N., & Maraite, H. (1987). Concentrations of the Herbicides Propyzamide, Chlorpropham, and of Their Metabolites in Soil and Lettuce Under Field Conditions. Bulletin of Environmental Contamination and Toxicology, 38(2), 240-246. https://doi.org/10.1007/BF01606668 (Original work published 1987)