Niland, D`arcy, author
Angus & Robertson, 1955
Buku Teks
Hardy, Frank
Gold Star Publication, 1971
Koleksi Publik
Palmer, Vance, author
Longman Cheshire, 1981
Buku Teks
Eldershaw, M. Barnard.
Harcourt, Brace and company, 1929
Buku Teks
Hardy, Frank
Gold Star Publication, 1971
Buku Teks