中国科学院数学与系统科学研究院期刊网
AMS
Weak Hopf Algebras Corresponding to Borcherds-Cartan Matrices
Li Xia YE, Zhi Xiang WU, Xue Feng Mei
Acta Mathematica Sinica . 2007, (10): 1729 -1744 .  DOI: 10.1007/s10114-007-0950-8