His well-known(a well-known person or thing is known about by a lot of people and is therefore famous or familiar. If someone is well-known for a particular activity, a lot of people know about them because of their involvement with that activity) book Pi Wei Lun (Treatise on the Stomach and Spleen) presented one of the most widely used traditional formulas: Ginseng and Astragalus Combination (Buzhong Yiqi Tang). 

The Li Dongyuan(李东垣Lǐ Dōngyuán),(also known as Li Gao; 1180-1252 A.D.) – Li is best known for his thesis that most diseases were due to injury to the stomach/spleen(your spleen is an organ(an organ is a part of your body that has a particular purpose or function, for example your heart or lungs) near your stomach that controls the quality of your blood) system, which occured as the result of intemperance in eating and drinking, overwork, and the seven emotions.