Rengganik, author
Universitas Indonesia, 2009
UI - Skripsi Open
Jansen, Marius B., author
Harvard University Press, 1967
Buku Teks
Restarick, Henry Bond
Yale University Press , 1931
Buku Teks
Hutagaol, Savitra B., author
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 1982
UI - Skripsi Membership
Wu, Y.C.
Amsterdam Djambatan 1950
Buku Teks