@article{GDZPPN002285606,
title = {\"Uber infinitesimale Kerne von Punktmengen in topologischen R\"aumen.},
journal = {Mathematische Annalen},
volume = {133},
year = {1957},
pages = {52-78},
zbl = {0077.16502},
url = {http://dml.mathdoc.fr/item/GDZPPN002285606}
}
Wagner, K. Über infinitesimale Kerne von Punktmengen in topologischen Räumen.. Mathematische Annalen, Tome 133 (1957) pp. 52-78. http://gdmltest.u-ga.fr/item/GDZPPN002285606/