In addition to the article posted above on El Tajin, I was also quoted in a National Geographic article on possible Olmec influence at the site of Zazacatla. To give some context for the short phrase credited to me in this article, here is the full statement I gave to the author:
Although the concentration of the Olmec heartland is located along the Gulf coast in modern Veracruz and Tabasco, the influence of the Formative period culture can be seen in the planning and organization of ceremonial centers and visual art forms of both contemporary and later civilizations throughout Mesoamerica. The Olmec need for materials, especially the precious and ritually important jade, developed a broad trade network. Evidence of this interaction has been discovered as much as 400 miles from the Olmec heartland in Guerrero. At sites such as Teopantecaunitlan sculptures depicting clear representations of Olmec supernatural figures have been found that date back to between 1200 and 800 BC. If further evidence of the recently discovered objects at Zazacatla indeed supports an interpretation of Olmec influence at the site, it would not be unheard of.