Doyle, Margaret, author
Women's Press, 1995
Buku Referensi
Palmer, E.H., author
Routledge & Kegan Paul, 1956
Buku Referensi
Lanyon-Orgill, Peter A., author
Luzac & Co., 1944
Buku Referensi
Boyle, John Andrew, author
Luzac & Company, 1949
Buku Referensi
Longman, 1984
Buku Referensi