Bolton, Maggie. <br/><br/>
Urton, Gary. Signs of the Inka khipu :   Binary coding in the Andean knotted-string records. xi, 202 pp., figs, tables, illus., bibliogr. Austin: Univ. Texas Press, 2003.  

 - London-ENK :   Board,   2006. 
 - p. 223-224 
 - Trimestral 
 - Vol. 12, no. 1, (Mar.2006) 
 - Journal of the Royal Antropological Institute. Incorporating Man ;   no. 1 .
 - Inglaterra.   Royal Antropological Institute. .
<br/><br/> Anthropology and history.  Book reviews. 
<br/><br/><br/>Art¡culo en inglés.