Oxford University Press, 1990
Buku Referensi
Merriam-Webster, 1998
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, author
Buku Teks