@article{05541096,
title = {Coverings, Laplacians, and heat kernels of directed graphs.},
journal = {The Electronic Journal of Combinatorics [electronic only]},
volume = {16},
year = {2009},
zbl = {1181.05059},
language = {en},
url = {http://dml.mathdoc.fr/item/05541096}
}
Brasseur, Clara E.; Grady, Ryan E.; Prassidis, Stratos. Coverings, Laplacians, and heat kernels of directed graphs.. The Electronic Journal of Combinatorics [electronic only], Tome 16 (2009) . http://gdmltest.u-ga.fr/item/05541096/