Willson, Robert W.. <br/><br/>
Astronomical notes on the maya codices. 

 - Massachusetts-US :   Peabody Museum of American Archaelogy and Ethnology,   1904. 
 - p. 1-63 :   il. 
 - Irregular 
 - Vol. VI, no. 3(1924) 
 - Papers. Peabody Museum of American Archaeology and Ethnology, Harvard University  ;   Vol. VI(3) .
 - Estados Unidos .   Harvard University. Estados Unidos .   Peabody Museum of American Archaeology and Ethnology. .
<br/><br/>Contens: Primitive astronomy; The lunar series in the dresden codex; The ahau equation; Data for determining the ahau equation; Outline of the typical maya planetary table; List of tables: I. Position of sun at sun at sunrise and sunset in latitude of copan; II. Eclipses on opplzer's "Canon", Visible in Yucatan, plates 91,92; III. Positions of venus and mars. Diferent hypotheses of value of ahau equation; IV. Planetary configurations as computed from the assumed values of 389,856; 487,956 for comparison.