Was the Beginning Day of the Maya Month Numbered Zero (or Twenty) or One?

An Introduction to the Study of the Maya Hieroglyphs

Commentary on the Maya Manuscript in the Royal Public Library of Dresden

Day Symbols of the Maya Year Sixteenth Annual Report of the Bureau of American Ethnology to the Secretary of the Smithsonian Institution, 1894-1895, Government Printing Office, Washington, 1897, pages 199-266.

Mayan Nomenclature

Memoranda on the Maya Calendars Used in the Books of Chilan Balam

Notes on Certain Maya and Mexican Manuscripts Third Annual Report of the Bureau of Ethnology to the Secretary of the Smithsonian Institution, 1881-82, Government Printing Office, Washington, 1884, pages 3-66