@ARTICLE{sens_based_extra,
author={Hinterm\"uller M. and Yousept, I.},
title="{A sensitivity-based extrapolation technique for the numerical solution 
of state-constrained optimal control problems}",
language="English",
journal="{ESAIM Control, Optimization and Calculus of
Variations (COCV)}",
volume="16",
number="3",
pages="503-522",
year="2010"
}