For example, see Balakrishnan, p. 1, and Gross (2003), p. 4, Zwillinger, p. 220. ↩
For example, see Bollobás, p. 7; Diestel, p. 28; Harary, p. 10. https://books.google.com/books?id=SbZKSZ-1qrwC&pg=PA7 ↩
Bollobás, pp. 39–40. https://books.google.com/books?id=SbZKSZ-1qrwC&pg=PA39 ↩
Gross (1998), p. 308. https://books.google.com/books?id=CRDMgj-DfdEC&pg=PA308 ↩