@article{CRMATH_2009__347_1-2_59_0,
     author = {Popa, Nicolae},
     title = {A characterization of upper triangular trace class matrices},
     journal = {Comptes Rendus. Math\'ematique},
     pages = {59--62},
     publisher = {Elsevier},
     volume = {347},
     number = {1-2},
     year = {2009},
     doi = {10.1016/j.crma.2008.11.020},
     language = {en},
     url = {http://www.numdam.org/articles/10.1016/j.crma.2008.11.020/}
}