Magdalena, Federico. “ARCHIVAL MATERIALS IN THE UNITED STATES ON MINDANAO, SULU AND PALAWAN (1899-1945)”. Mindanao Journal 19, no. 1-2 (June 9, 2025): 355–374. Accessed March 4, 2026. https://msu-mindanaojournal.com/index.php/ojs/article/view/355.