Abinales, Patricio N.; Amoroso, Donna J. (2005). "New States and Reorientations 1368-1764". State and Society in the Philippines. Lanham, Md.: Rowman & Littlefield. pp. 53, 55. ISBN0742510247. Retrieved January 15, 2015.
Constantino, Renato; Constantino, Letizia R. (1975). "Chapter V - The Colonial Landscape". The Philippines: A Past Revisited (Vol. I) (Sixteenth Printing (January 1998) ed.). Manila, Philippines: Renato Constantino. pp. 60–61. ISBN971-895-800-2. OL9180911M.