There might be other source material factored on but not mentioned. (I don’t think the Mayans kept a written history, but encounters with other peoples might have been preserved in those peoples’ historical tradition.) Or this might be an anthropologist way out in left field.
The Mayans kept written records, but the Spanish destroyed most of them. However, their stelae, which are carved stone monuments placed in ceremonial centers, do record some of their historical events and their rulers’ achievements, military triumphs, and their descent. See also the paintings in the temple at Bonampak.
Actually, they did. But the missionaries destroyed all but a few as "works of the devil", and nobody has managed to translate the few that remain.