@article{10_4153_CMB_1976_040_x,
     author = {Borwein, J. and O{\textquoteright}Brien, R.},
     title = {Tangent {Cones} and {Convexity}},
     journal = {Canadian mathematical bulletin},
     pages = {257--261},
     year = {1976},
     volume = {19},
     number = {3},
     doi = {10.4153/CMB-1976-040-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1976-040-x/}
}