@article{10_1017_S0017089500001221,
     author = {Fillmore, P. A. and Williams, J. P.},
     title = {Some convexity theorems for matrices},
     journal = {Glasgow mathematical journal},
     pages = {110--117},
     year = {1971},
     volume = {12},
     number = {2},
     doi = {10.1017/S0017089500001221},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500001221/}
}