K3
Artigas y Cuerva, Manuel. Civilización prehispana: informes ineditos sobre Filipinas (Prehispanic Civilization: unpublished information about the Philipppines published in Filipino Renaissance)published in Renacimiento Filipino 3^rd anniversary special issue. July 1913. pp.73-74.

From W.H. Scott. Prehispanic Source Materials for the Study of Philippine History, revised edtion, 1984. pp. 107, 158.