Percival, W. Keith. 1964. A Grammar of Toba-Batak. (Doctoral dissertation, New Haven: Yale University; 220pp.)
@phdthesis{gPercivalTobaBatak1964, author = {Percival, W. Keith}, pages = {220}, school = {New Haven: Yale University}, title = {A Grammar of Toba-Batak}, year = {1964} }