“The Maya.” Western World, by Christopher L. Salter, Holt McDougal, 2012, pp. 118–133. Unit 2.
https://www.thoughtco.com/ancient-maya-economy-and-trade-2136168
https://www.history.com/topics/maya
https://www.quora.com/Why-did-the-Egyptian-Mayan-and-Japanese-civilizations-create-the-same-structures-pyramids
https://swittersb.wordpress.com/2012/04/27/earthquakes-mayan-calendar-bora-bora/
http://www.hartford-hwp.com/archives/41/216.html
https://www.thoughtco.com/ancient-maya-economy-and-trade-2136168
https://www.history.com/topics/maya
https://www.quora.com/Why-did-the-Egyptian-Mayan-and-Japanese-civilizations-create-the-same-structures-pyramids
https://swittersb.wordpress.com/2012/04/27/earthquakes-mayan-calendar-bora-bora/
http://www.hartford-hwp.com/archives/41/216.html