@article{10_1017_S0017089505002685,
     author = {ALZER, HORST},
     title = {ON {A} {CONVEXITY} {THEOREM} {OF} {RUSKAI} {AND} {WERNER} {AND} {RELATED} {RESULTS}},
     journal = {Glasgow mathematical journal},
     pages = {425--438},
     year = {2005},
     volume = {47},
     number = {3},
     doi = {10.1017/S0017089505002685},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089505002685/}
}