Wells, M. J. M.; Yu, L. Z. (2000). "Solid-phase extraction of acidic herbicides". Journal of Chromatography A. 885 (1–2): 237–250. doi:10.1016/S0021-9673(00)00206-5. PMID10941675.
Wells, M. J. M.; Yu, L. Z. (2000). "Solid-phase extraction of acidic herbicides". Journal of Chromatography A. 885 (1–2): 237–250. doi:10.1016/S0021-9673(00)00206-5. PMID10941675.