@article{JCA_2018_25_3_JCA_2018_25_3_a10,
     author = {M. Himmel and J. Matkowski},
     title = {Directional {Convexity} and {Characterizations} of {Beta} and {Gamma} {Functions}},
     journal = {Journal of convex analysis},
     pages = {927--938},
     year = {2018},
     volume = {25},
     number = {3},
     url = {http://geodesic.mathdoc.fr/item/JCA_2018_25_3_JCA_2018_25_3_a10/}
}