@article{JIS_2009__12_6_a3,
     author = {Hirschhorn, Michael D.},
     title = {On recurrences of {Fahr} and {Ringel} arising in graph theory},
     journal = {Journal of integer sequences},
     publisher = {mathdoc},
     volume = {12},
     number = {6},
     year = {2009},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/JIS_2009__12_6_a3/}
}