0.54 William R. Fowler_ Jr.Arthur A. Demarest Helen V. Michel Frank Asaro Fred Stross, Sources of Obsidian from El Mirador Guatemala: New Evidence on Preclassic Maya Interaction, American Anthropologist, 1989.

{ maya political state late }	0.54
{ university press american pp }	0.15
{ archaeological archaeology sites american }	0.08
{ de mexico spanish san }	0.07