King, Victor T.
Blackwell, 1993
Buku Teks SO
Mackinnon, John Ramsay
[publisher not identified], [date of publication not identified]
Buku Teks SO
Robinson, Danielm
Lonely Publications Pty Ltd, 2011
Buku Referensi
Bock, Carl
Graham Bush, 1988
Buku Teks
Pascal Couderc and Kenneth Sillander, editors
Nias Press, 2012
Buku Teks SO