@article{MAN_1967__173_161599,
     author = {Juan Jorge Sch\"afer},
     title = {Diameter, {Perimeter,} and {Girth} of {Spheres}},
     journal = {Mathematische Annalen},
     pages = {59--82},
     year = {1967},
     volume = {173},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/MAN_1967__173_161599/}
}