Headland, T. N., & Headland, J. (1965). Libro a pegbasaan: Casiguran Dumagat (Agta). Summer Institute of Linguistics in cooperation with the Bureau of Public Schools and the Institute of National Language of the Department of Education.
Chicago-referens (17:e uppl.)Headland, Thomas N., och Janet Headland. Libro a Pegbasaan: Casiguran Dumagat (Agta). Manila: Summer Institute of Linguistics in cooperation with the Bureau of Public Schools and the Institute of National Language of the Department of Education, 1965.
MLA-referens (9:e uppl.)Headland, Thomas N., och Janet Headland. Libro a Pegbasaan: Casiguran Dumagat (Agta). Summer Institute of Linguistics in cooperation with the Bureau of Public Schools and the Institute of National Language of the Department of Education, 1965.