@article{01924311,
title = {Two models for contraction operators. (Deux mod\`eles pour les op\'erateurs de contraction.)},
journal = {ELA. The Electronic Journal of Linear Algebra [electronic only]},
volume = {9},
year = {2002},
pages = {171-189},
zbl = {1053.47005},
language = {en},
url = {http://dml.mathdoc.fr/item/01924311}
}
Bendoukha, Berrabah. Two models for contraction operators. (Deux modèles pour les opérateurs de contraction.). ELA. The Electronic Journal of Linear Algebra [electronic only], Tome 9 (2002) pp. 171-189. http://gdmltest.u-ga.fr/item/01924311/