中国科学院数学与系统科学研究院期刊网
AMS
Horizontal Connection and Horizontal Mean Curvature in Carnot Groups
Kang Hai TAN, Xiao Ping YANG
Acta Mathematica Sinica . 2006, (3): 701 -710 .  DOI: 10.1007/s10114-005-0572-y