APA (7th ed.) Citation

Orosa, S. Y. (1923). The Sulu archipelago and its people. World Book Co.

Chicago Style (17th ed.) Citation

Orosa, Sixto Y. The Sulu Archipelago and Its People. Yonkers-on-Hudson, N.Y: World Book Co, 1923.

MLA (9th ed.) Citation

Orosa, Sixto Y. The Sulu Archipelago and Its People. World Book Co, 1923.