Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{MZ_1981__176_183658, author = {Rainer Colgen}, title = {Invariance of {Essential} {Spectra.}}, journal = {Mathematische Zeitschrift}, pages = {489--494}, publisher = {mathdoc}, volume = {176}, year = {1981}, zbl = {0439.47007}, url = {http://geodesic.mathdoc.fr/item/MZ_1981__176_183658/} }
Rainer Colgen. Invariance of Essential Spectra.. Mathematische Zeitschrift, Tome 176 (1981), pp. 489-494. http://geodesic.mathdoc.fr/item/MZ_1981__176_183658/