@article{10_4153_CJM_1972_012_1,
     author = {Park, Ralph},
     title = {Topics in {Direct} {Differential} {Geometry}},
     journal = {Canadian journal of mathematics},
     pages = {98--148},
     year = {1972},
     volume = {24},
     number = {1},
     doi = {10.4153/CJM-1972-012-1},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1972-012-1/}
}