Why is the combined treatment of copper and aluminum more toxic to citrus than single factor treatment? - Chen, Wen-Shu; Wu, Ti; Xia, Tian-Tian; Tong, Liang-Yuan; Lu, Fei; Ye, Xin; Guo, Jiuxin; Huang, Zeng-Rong; Yang, Lin-Tong; Chen, Li-Song (Journal of Hazardous Materials, 2025)