D Hosler, SL Burkett ja MJ Tarkanian:Prehistoric Polymers: Rubber Processing in Ancient Mesoamerica.Science,1999, nro 284, s. 1988–1991.PubMed:10373117doi:10.1126/science.284.5422.1988
D Hosler, SL Burkett ja MJ Tarkanian:Prehistoric Polymers: Rubber Processing in Ancient Mesoamerica.Science,1999, nro 284, s. 1988–1991.PubMed:10373117doi:10.1126/science.284.5422.1988