@article{ELA_2011__22__a74,
     author = {Kuzma, Bojan and Li, Chi-Kwong and Rodman, Leiba},
     title = {Tracial numerical ranges and linear dependence of operators},
     journal = {The electronic journal of linear algebra},
     pages = {22--52},
     publisher = {mathdoc},
     volume = {22},
     year = {2011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ELA_2011__22__a74/}
}