Wichman, K.
New York, David Mckay Company
Buku Referensi
Barnhart, Clarence L.
Garden City, New York, Doubleday, 1967
Buku Referensi
Breul, Karl
Boston D.C. Heath 1936
Buku Referensi
Fowler, H. W. (Henry Watson), 1858-1933
New York Oxford University Press 1965
Buku Referensi
Chapman, Robert L.
London Pan Books 1988
Buku Referensi