Sitsen, Peter H.W.
Buku Teks SO
Preger W.
F. W. Cheshire pty. ltd. , 1944
Buku Teks SO
edited by Pieter Honig and Frans Verdoorn
Board for the Netherlands Indies, 1945
Buku Referensi
Polak, J.J.
Netherlands and Netherlands Indies Council of the Institute of Pacific Relations , 1939
Buku Teks
Division of Commerce of the Department of Agriculture, Industry and Commerce, 1930
Buku Teks SO