Got distracted thinking about the Olmec and the Mother/Sister Culture debate.
A few relevant references:
Blomster, Jeffrey P., Hector Neff, and Michael D. Glascock. 2005. Olmec Pottery Production and Export in Ancient Mexico Determined through Elemental Analysis. Science 307:1068–72.
Flannery, Kent V., and Joyce Marcus. 2000. Formative Mexican Chiefdoms and the Myth of the “Mother Culture”. Journal of Anthropological Archaeology 19:1–37.
Flannery, Kent V., Andrew K. Balkansky, Gary M. Feinman, David C. Grove, Joyce Marcus, Elsa M. Redmond, Robert G. Reynolds, Robert J. Sharer, Charles S. Spencer, and Jason Yaeger. 2005. Implications of New Petrographic Analysis for the Olmec “Mother Culture” Model. Proceedings of the National Academy of Sciences of the United States of America 102:11219–23.
Grove, David C. 1997. Olmec Archaeology: A Half Century of Research and Its Accomplishments. Journal of World Prehistory 11:51–101.
Pool, Christopher A. 2006. Current Research on the Gulf Coast of Mexico. Journal of Archaeological Research 14:189–241.
Wilk, Richard R. 2004. Miss Universe, the Olmec and the Valley of Oaxaca. Journal of Social Archaeology 4:81–98.