中国科学院数学与系统科学研究院期刊网
Shod Subcategories and Contravariant Finite Subcategories of Dual Extension Algebras
Xian Neng DU
Acta Mathematica Sinica, Chinese Series . 2004, (3): 553 -558 .  DOI: 10.12386/A2004sxxb0070