@article{00469031,
title = {Graphs and functional equations.},
journal = {Annales Academiae Scientiarum Fennicae. Mathematica},
volume = {18},
year = {1993},
pages = {125-146},
zbl = {0785.30011},
language = {en},
url = {http://dml.mathdoc.fr/item/00469031}
}
Hansen, Lowell J.; Shapiro, Harold S. Graphs and functional equations.. Annales Academiae Scientiarum Fennicae. Mathematica, Tome 18 (1993) pp. 125-146. http://gdmltest.u-ga.fr/item/00469031/