Xiong, Fei, Xiao-Kang Li, Mei Xu, Shu-Ping Zhang, Fen-Er Chen, Bin Liao, Hao-Jie Hua, and Jun-Hao He. 2014. “Development of Two Scalable Industrial Process for Cinchona Alkaloid Catalyst Recovery: Application to the Large-Scale Production of (+)-Biotin”. Asian Journal of Chemistry 26 (12):3659-60. https://doi.org/10.14233/ajchem.2014.16782.