1. The splendid tomb of Temple I at Tikal, Guatemala;Trik;Expedition,1963
2. Historical data in the inscriptions of Yaxchilan;Proskouriakoff;Estudios de Cultura Maya,1963
3. Mundurucu religion;Murphy;University of California Publications in American Archaeology and Ethnology, Berkeley,1958
4. Gloss M. 1977 Decipherment of the Maya zero hieroglyph. Paper presented at the International Symposium on Maya Art, Architecture, Archaeology and Hieroglyphic Writing, Guatemala City.