@article{1103857597, author = {Collins, C. B.}, title = {More qualitative cosmology}, journal = {Comm. Math. Phys.}, volume = {20}, number = {1}, year = {1971}, pages = { 137-158}, language = {en}, url = {http://dml.mathdoc.fr/item/1103857597} }
Collins, C. B. More qualitative cosmology. Comm. Math. Phys., Tome 20 (1971) no. 1, pp. 137-158. http://gdmltest.u-ga.fr/item/1103857597/