@article{10_4153_CJM_1973_104_5,
     author = {Campbell, Douglas Michael},
     title = {The {Radius} of {Convexity} of a {Linear} {Combination} of {Functions} in or u\ensuremath{\alpha}},
     journal = {Canadian journal of mathematics},
     pages = {982--985},
     year = {1973},
     volume = {25},
     number = {5},
     doi = {10.4153/CJM-1973-104-5},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1973-104-5/}
}