中国科学院数学与系统科学研究院期刊网
On the Unitriangular Group over the Integral Ring
He Guo LIU, Zuo HuiWU, Fang ZHOU
Acta Mathematica Sinica, Chinese Series . 2011, (2): 211 -218 .  DOI: 10.12386/A2011sxxb0022