@article{CRMATH_2012__350_7-8_399_0, author = {Colombo, Fabrizio and Sabadini, Irene}, title = {On some notions of spectra for quaternionic operators and for \protect\emph{n}-tuples of operators}, journal = {Comptes Rendus. Math\'ematique}, pages = {399--402}, publisher = {Elsevier}, volume = {350}, number = {7-8}, year = {2012}, doi = {10.1016/j.crma.2012.03.017}, language = {en}, url = {http://www.numdam.org/articles/10.1016/j.crma.2012.03.017/} }