@article{01693764,
title = {On the lack of null-controllability of the heat equation on the half space.},
journal = {Portugaliae Mathematica. Nova S\'erie},
volume = {58},
year = {2001},
pages = {1-24},
zbl = {0991.35010},
language = {en},
url = {http://dml.mathdoc.fr/item/01693764}
}
Micu, S.; Zuazua, E. On the lack of null-controllability of the heat equation on the half space.. Portugaliae Mathematica. Nova Série, Tome 58 (2001) pp. 1-24. http://gdmltest.u-ga.fr/item/01693764/