Boehm, E.A., author
Longman Chesire, 1979
Buku Teks
Boehm, E.A., author
Longman, 1971
Buku Teks
Tim Lindsey, Dave McRae, editors
Hart Publishing, 2018
Buku Teks
Austin, A.G.
Isac Pitman and Sons, 1965
Buku Teks
Turner, Ian, author
Hale & Iremonger, 1979
Buku Teks