@article{DM_2004_16_3_a8,
     author = {V. A. Kolmykov},
     title = {On the characteristic polynomials of periodic graphs},
     journal = {Diskretnaya Matematika},
     pages = {153--159},
     year = {2004},
     volume = {16},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_2004_16_3_a8/}
}