中国科学院数学与系统科学研究院期刊网
AMS
Poincaré and Sobolev Inequalities for Vector Fields Satisfying Hörmander's Condition in Variable Exponent Sobolev Spaces
Xia LI, Guo Zhen LU, Han Li TANG
Acta Mathematica Sinica . 2015, (7): 1067 -1085 .  DOI: 10.1007/s10114-015-4488-x