Boyle, John Andrew
Luzac & Company, 1949
Buku Referensi
Skeat, Walter W.
The Clarendon Press, 1948
Buku Referensi
David B. Guralnik, general editor
The World Publishing Co., 1956
Buku Referensi
Bird, Roger
Sweet & Maxwell, 1983
Buku Teks
Fowler, H. W. (Henry Watson), 1858-1933
Buku Teks