Lancion, Jr., Conrado M.; cartography by de Guzman, Rey (1995) „The Provinces; Aurora“, Fast Facts about Philippine Provinces, The 2000 Millenium, Makati, Metro Manila, Philippines: Tahanan Books, გვ. 28. ISBN971-630-037-9. ციტირების თარიღი: 4 December 2015.
National Historical Commission of the Philippines. „History of Baler“. National Historical Commission of the Philippines. დაარქივებულია ორიგინალიდან — მაისი 14, 2013. ციტირების თარიღი: 2012-03-09. ციტატა: „When military district of El Príncipe was created in 1856, Baler became its capital...On June 12, 1902 a civil government was established, moving the district of El Príncipe away from the administrative jurisdiction of Nueva Ecija...and placing it under the jurisdiction of Tayabas Province.“
National Historical Commission of the Philippines. „History of Baler“. National Historical Commission of the Philippines. დაარქივებულია ორიგინალიდან — მაისი 14, 2013. ციტირების თარიღი: 2012-03-09. ციტატა: „When military district of El Príncipe was created in 1856, Baler became its capital...On June 12, 1902 a civil government was established, moving the district of El Príncipe away from the administrative jurisdiction of Nueva Ecija...and placing it under the jurisdiction of Tayabas Province.“