Bone, Hugh A., author
McGraw-Hill, 1965
Buku Teks
Reeve, David, author
Oxford University Press, 1985
Buku Teks
Rawson, D.W.
Longmans, 1966
Buku Teks
West, Katharine
F.W. Cheshire, 1965
Buku Teks
Jaensch, Dean Harold, author
Allen & Unwin, 1989
Buku Teks