@article{00772778,
title = {Centers in iterated line graphs.},
journal = {Acta Mathematica Universitatis Comenianae. New Series},
volume = {61},
year = {1992},
pages = {237-241},
zbl = {0821.05022},
language = {en},
url = {http://dml.mathdoc.fr/item/00772778}
}
Knor, M.; Niepel, L.; Olts, L. Centers in iterated line graphs.. Acta Mathematica Universitatis Comenianae. New Series, Tome 61 (1992) pp. 237-241. http://gdmltest.u-ga.fr/item/00772778/