[http://www.asociaciontikal.com/sim1988/pdf/24.88%20-%20James%20Brady%20-%20en%20PDF.pdf]*Andrea Stone—Regional Variation in Maya Cave Art.
[http://www.asociaciontikal.com/sim1988/pdf/24.88%20-%20James%20Brady%20-%20en%20PDF.pdf]* Andrea Stone—Regional Variation in Maya Cave Art.