1. Keys, pp. 5, 189–190.

2. Richard E. W. Adams, Ancient Civilizations of the New World (1997), pp. 50–51.

3. Joyce Marcus, «The Origins of Mesoamerican Writing», Annual Review of Anthropology, 5 (1976), p. 37.

4. Ibid., pp. 39–40.

5. Elizabeth Hill Boone, Cycles of Time and Meaning in the Mexican Books of Fate (2007), p. 14.

6. Keys, pp. 186-87; Adams, pp. 43–44; George L. Cowgill, «State and Society at Teotihuacan, Mexico», Annual Review of Anthropology, 26 (1997), pp. 129–130.

7. Saburo Sugiyama, «Worldview Materialized in Teotihuacan, Mexico», Latin American Antiquity, 4: 2 (1993), p. 105.

8. Richard Haly, «Bare Bones: Rethinking Mesoamerican Divinity», History of Religions, 31: 3 (1992), pp. 280–281.

9. Ibid., p. 287.

10. Boone, p. 13.

11. Haly, p. 297; Keys, p. 193.

12. Rene Millon, «Teotihuacan: City, State and Civilization», in Victoria Reifler Bricker, ed., Supplement to the Handbook of Middle American Indians, vol. 1, pp. 235–238; Norman Yoffee, ed., The Collapse of Ancient States and Civilizations (1988), pp. 149ff; Keys, pp. 192–193, 197–198.

13. Ernesto Gonzalez Licon, Vanished Mesoamerican Civilizations, trans. Andrew Ellis (1991), pp. 81–83.

14. Ibid., p. 92.