TY  - JOUR
AU  - Ge, Zhong
TI  - Collapsing Riemannian Metrics to Carnot-Caratheodory Metrics and Laplacians to Sub-Laplacians
JO  - Canadian journal of mathematics
PY  - 1993
SP  - 537
EP  - 553
VL  - 45
IS  - 3
UR  - http://geodesic.mathdoc.fr/articles/10.4153/CJM-1993-028-6/
DO  - 10.4153/CJM-1993-028-6
ID  - 10_4153_CJM_1993_028_6
ER  -