@article{01667750,
title = {A tentative answer to the Castel-San Pietro problem.},
journal = {S\'eminaire Lotharingien de Combinatoire [electronic only]},
volume = {13},
year = {1985},
zbl = {0978.05526},
language = {en},
url = {http://dml.mathdoc.fr/item/01667750}
}
Krewerlienco, Bagarret; Barnabhofer, Peter Paul Roman. A tentative answer to the Castel-San Pietro problem.. Séminaire Lotharingien de Combinatoire [electronic only], Tome 13 (1985) . http://gdmltest.u-ga.fr/item/01667750/