Masterpiece? Do you mean classics or research? I think the most important classics, of course, are books like Tao Te Ching, Zhuangzi, Taiping Ching, Lao Zi's Notes on Xianger and Li Jiao's Fifteen Treatises. There is no need to look for them on the Internet. If you study monographs, there are a group of university professors at present, but I suggest you look at the book "Taoism and Health" by Chen Yingning, the president of the second Taoist Association. And teacher Li's summary of Taoism. They are considered to be people within the church, more profound than sociologists. There are several famous sociologists. Mou, Zhan Shichuang and Xu are three of them. They are all old gentlemen.