@article{10_1017_S0008439500030575,
     author = {Helfenstein, H.G.},
     title = {Introduction to differential geometry and {Riemannian} geometry, by {E.} {Kreyszig.} {University} of {Toronto} {Press,} 1968. xii + 370 pages.},
     journal = {Canadian mathematical bulletin},
     pages = {371--372},
     year = {1969},
     volume = {12},
     number = {3},
     doi = {10.1017/S0008439500030575},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0008439500030575/}
}