E. Estrada, J.A. de la Pena, N. Hatano, Walk Entropies in Graphs. Linear Algebra and its Applications 433 2013, 235-244.

E. Estrada, J.A. de la Pena, N. Hatano, Walk Entropies in Graphs. Linear Algebra and its Applications 433 2013, 235-244. [PDF]