@article{articleaea17c0e,
title   = {Duality and the Poincaré-Hopf inequalities},
author = {Bertolim, M. A. and Biasi, Carlos and Rezende, K. A. de},
year = {2011},
doi = {10.1007/s10958-011-0461-0},
journal   = {Journal of Mathematical Sciences}
}