J.P.J.P.SarumpaetJ.P.J.P., The Samosir dialect of Toba-Batak, [w:] PaulP.Geraghty, LoisL.Carrington, S.A.S.A.Wurm (red.), FOCAL II: Papers from the Fourth International Conference on Austronesian Linguistics, Canberra: Department of Linguistics, Research School of Pacific Studies, Australian National University, 1986 (Pacific Linguistics C-94), s. 73–86, DOI: 10.15144/PL-C94.73, ISBN 978-0-85883-345-6, OCLC570220350 [dostęp 2022-09-13](ang.).
J.P.J.P.SarumpaetJ.P.J.P., The Samosir dialect of Toba-Batak, [w:] PaulP.Geraghty, LoisL.Carrington, S.A.S.A.Wurm (red.), FOCAL II: Papers from the Fourth International Conference on Austronesian Linguistics, Canberra: Department of Linguistics, Research School of Pacific Studies, Australian National University, 1986 (Pacific Linguistics C-94), s. 73–86, DOI: 10.15144/PL-C94.73, ISBN 978-0-85883-345-6, OCLC570220350 [dostęp 2022-09-13](ang.).
J.P.J.P.SarumpaetJ.P.J.P., The Samosir dialect of Toba-Batak, [w:] PaulP.Geraghty, LoisL.Carrington, S.A.S.A.Wurm (red.), FOCAL II: Papers from the Fourth International Conference on Austronesian Linguistics, Canberra: Department of Linguistics, Research School of Pacific Studies, Australian National University, 1986 (Pacific Linguistics C-94), s. 73–86, DOI: 10.15144/PL-C94.73, ISBN 978-0-85883-345-6, OCLC570220350 [dostęp 2022-09-13](ang.).
MaruliM.Butar-ButarMaruliM., The Phonology of Batak, Indiana University, 1961, s. 1, OCLC63864552(ang.).