@article{oai:repository.dl.itc.u-tokyo.ac.jp:00040237, author = {Kotani, Motoko and Sunada, Toshikazu}, issue = {1}, journal = {Journal of mathematical sciences, the University of Tokyo}, month = {}, pages = {7--25}, title = {Zeta Functions of Finite Graphs}, volume = {7}, year = {2000} }