@article{CRMATH_2017__355_10_1077_0,
     author = {Bourin, Jean-Christophe and Mhanna, Antoine},
     title = {Positive block matrices and numerical ranges},
     journal = {Comptes Rendus. Math\'ematique},
     pages = {1077--1081},
     publisher = {Elsevier},
     volume = {355},
     number = {10},
     year = {2017},
     doi = {10.1016/j.crma.2017.10.006},
     language = {en},
     url = {http://www.numdam.org/articles/10.1016/j.crma.2017.10.006/}
}