@article{1029000034,
author = {Arhangel'ski\u\i , A. V. and Franklin, S. P.},
title = {Ordinal invariants for topological spaces.},
journal = {Michigan Math. J.},
volume = {15},
number = {1},
year = {1968},
pages = { 313-320},
language = {en},
url = {http://dml.mathdoc.fr/item/1029000034}
}
Arhangel'skiĭ, A. V.; Franklin, S. P. Ordinal invariants for topological spaces.. Michigan Math. J., Tome 15 (1968) no. 1, pp. 313-320. http://gdmltest.u-ga.fr/item/1029000034/