Application of waste derived magnetic acid-base bifunctional CoFe/biochar/CaO as an efficient catalyst for biodiesel production from waste cooking oil - Shaige Xia; Junyu Tao; Yihua Zhao; Yanhui Men; Chao Chen; Yongjie Hu; Guangbin Zhu; Yiwei Chu; Beibei Yan; Guanyi Chen (Chemosphere, 2024)