1. [1] Watts, D. J. and Strogatz, S. H., Collective Dynamics of ‘Small-World’ Networks, Nature, Vol. 393(6684), 440-442 (1998).
2. [2] Barabási, A. L. and Albert, R., Emergence of Scaling in Random Networks, Science, Vol. 286(5439), 509-512 (1999).
3. [3] Odagaki, T., The Physics of Connectivity, －Percolation Theory and Complex Networks Theory－, Shokabo, Tokyo (2020).
4. [4] Yakubo, K., Complex Networks and Their Structures, Kyoritsu Pub., Tokyo (2013).
5. [5] Masuda, N. and Konno, N., Science of Complex Networks, Sangyo Tosho, Tokyo (2005).