@article{1183507348,
author = {Springer, C. E.},
title = {Union curves and union curvature},
journal = {Bull. Amer. Math. Soc.},
volume = {51},
number = {11},
year = {1945},
pages = { 686-691},
language = {en},
url = {http://dml.mathdoc.fr/item/1183507348}
}
Springer, C. E. Union curves and union curvature. Bull. Amer. Math. Soc., Tome 51 (1945) no. 11, pp. 686-691. http://gdmltest.u-ga.fr/item/1183507348/