Johnson, Alvin S., author
Hearh & Co., 1911
Buku Teks
Hague, Douglas C.
Longmans, Green and Co., 1955
Buku Teks
Hyman, David N., author
Richard D. Irwin, 1971
Buku Teks
Hicks, John R., author
The Clarendon Press, 1952
Buku Teks
Becker, William E., author
Prentice-Hall, 1971
Buku Teks