@article{AM2_1987__34_137221,
     author = {Erhard Heil},
     title = {Extensions of an inequality of {Bonnesen} to {D-dimensional} space and curvature conditions for convex bodies.},
     journal = {Aequationes mathematicae},
     pages = {35--60},
     publisher = {mathdoc},
     volume = {34},
     year = {1987},
     zbl = {0626.52015},
     url = {http://geodesic.mathdoc.fr/item/AM2_1987__34_137221/}
}