Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{MZ_1968__108_171087, author = {Heinrich P. Lotz}, title = {\"Uber das {Spektrum} positiver {Operatoren.}}, journal = {Mathematische Zeitschrift}, pages = {15--32}, publisher = {mathdoc}, volume = {108}, year = {1968}, zbl = {0179.18002}, url = {http://geodesic.mathdoc.fr/item/MZ_1968__108_171087/} }
Heinrich P. Lotz. Über das Spektrum positiver Operatoren.. Mathematische Zeitschrift, Tome 108 (1968), pp. 15-32. http://geodesic.mathdoc.fr/item/MZ_1968__108_171087/