Macapagal, Diosdado (1964) Proclamation No. 325, s. 1964. Official Gazette.
Maceda, M.N. (1964) The culture of the Mamanua (northeast Mindanaio): as compared with that of the other Negritos of Southeast Asia. San Carlos publications . Catholic Trade School.
Miller, Jeanne (1964) The role of verb stems in the Mamanwa kernel verbal clauses. Oceanic Linguistics, 3 (1). pp. 87-100.