Burrell, R.E.C.
Wheaton , 1980
Buku Teks
Davidson, B.R., author
Melbourne University Press, 1972
Buku Teks
Martin, Anne
Routledger Kegan Paul , 1958
Buku Teks
Sie, Kwat-soen
Centre for Agricultural Publishing and Documentation, 1968
Buku Teks
Black, John Donald
Macmillan, 1953
Buku Teks