by Lai, Hong-Jian, Li, Xiangwen, Shao, Yehong, Zhan, Mingquan
Published in Acta mathematica Sinica. English series (01.03.2011)

by 최재영, Jae Young Choi, 임미나, Mi Na Lim
Published in 중국연구 (30.01.2009)

by Chen, Gui-Qiang, Osborne, Dan, Qian, Zhongmin
Published in Acta mathematica scientia (01.07.2009)