@article{GDZPPN00221508X,
title = {On Gel'fand-Graev characters of reductive groups with disconnected centre.},
journal = {Journal f\"ur die reine und angewandte Mathematik},
volume = {485},
year = {1997},
pages = {131-148},
zbl = {0880.20033},
url = {http://dml.mathdoc.fr/item/GDZPPN00221508X}
}
Lehrer, G.I.; Michel, J.; Digne, F. On Gel'fand-Graev characters of reductive groups with disconnected centre.. Journal für die reine und angewandte Mathematik, Tome 485 (1997) pp. 131-148. http://gdmltest.u-ga.fr/item/GDZPPN00221508X/