@article{MZ_1984__188_173519,
     author = {Ernst A. Ruh and Josef Bemelmans and Min-Oo},
     title = {Smoothing {Riemannian} {Metrics.}},
     journal = {Mathematische Zeitschrift},
     pages = {69--74},
     publisher = {mathdoc},
     volume = {188},
     year = {1984},
     zbl = {0536.53044},
     url = {http://geodesic.mathdoc.fr/item/MZ_1984__188_173519/}
}