Theodorson, George A.
Barnes & Noble Books, 1969
Buku Referensi
edited by Henry Praty Fairchild
Littlefield, Adams & Co., 1962
Buku Referensi
Jary, David
Harper Collins, 1991
Buku Teks
Garner, Bryan A.
Oxford University Press, 1995
Buku Referensi
Fowler, H. W. (Henry Watson), 1858-1933
New York Oxford University Press 1965
Buku Referensi