(iti Ingles) Adelaar, Alexander, The Austronesian Languages of Asia and Madagascar: A Historical Perspective, The Austronesian Languages of Asia and Madagascar, pp. 1–42, Routledge Language Family Series, Londres: Routledge, 2005, ISBN0-7007-1286-0
(iti Indones) Siregar, Ahmad Samin, Kamus Bahasa Angkola/Mandailing Indonesia, Jakarta: Pusat Pembinaan Dan Pengembangan Bahasa, Departemen Pendidikan Dan Kebudayaan, 1977.