Helpful resources. Hopefully for any student of Davao history, this will prove beneficial.
Hardprint
The Wild Tribes of Davao District, Mindanao, by Fay-Cooper Cole
The Inhabitants of the Philippines, by Frederic H. Sawyer
The Philippine Islands, 1493-1898, V7, 1588-1591, by Emma Helen Blair
Exploración del territorio de Davao by Rajal y Larré, Joaquín, 1847-
The Japanese in Colonial Southeast Asia – edited by Saya Shiraishi, Takashi Shiraishi
Chronicling America – Historic American Newspapers
The Origins of Banana-fibre Cloth in the Ryukyus, Japan – By Katrien Hendrickx
Japan and South East Asia: From the Meiji Restoration to 1945, Volume 1 edited by Wolf Mendl
Japan Views the Philippines, 1900-1944 By Lydia N. Yu-Jose
Web and Digital Archives
Antonio Figueroa – Edge Davao column on Davao history
Anderson Villa – Davao Today column on Davao history
Davao Museum of History and Ethnography
DAVAO: It’s History, Culture, Politics, Economy and Progress
Charles F. Clagg Photograph Collection – 1920, June July
Philippine Photographs Digital Archive, Special Collections Library, University of Michigan
Retrato – The Photo Archive of the Filipinos Heritage Library
National Archives of the Philippines
Davao City Library and Information Center
Monash University Repository – Terrain Study No. 92 – Davao Gulf – Sarangani Bay
Japan Center for Asian Historical Research
Hoji Shinbun – Japanese Diaspora Initiative – Hoover Institution
Davao Times – published by the Davao branch of the Manira Shinbunsha