@article{MAN_1984__267_163897,
     author = {Arthur E. Fischer and Anthony J. Tromba},
     title = {On a {Purely} {?Riemannian}},
     journal = {Mathematische Annalen},
     pages = {311--346},
     publisher = {mathdoc},
     volume = {267},
     year = {1984},
     zbl = {0518.32015},
     url = {http://geodesic.mathdoc.fr/item/MAN_1984__267_163897/}
}