Hettema, H.
W.E.J.Tjeenk Willink, 1931
Buku Referensi
Presser, J. (Jacob)
Uitgave van, 1939
Buku Referensi
edited by Geoffrey Barraclough
Times Books, 1984
Buku Referensi
The George F. Cram, 1952
Buku Referensi
Wheatley, Paul
University Of Malaya Press, 1961
Buku Teks