@article{ASCFM_1962__8_2_183_0,
     author = {Walker, A. G.},
     title = {Geometry and cosmology},
     journal = {Annales de la facult\'e des sciences de l'universit\'e de Clermont. Math\'ematiques},
     pages = {183--187},
     publisher = {UER de Sciences exactes et naturelles de l'Universit\'e de Clermont},
     volume = {8},
     number = {2},
     year = {1962},
     language = {en},
     url = {http://archive.numdam.org/item/ASCFM_1962__8_2_183_0/}
}