Lower, Arthur R.M.
The Ryerson Press, 1952
Buku Teks
Lower, Arthur R.M.
Longmans, Green and Company, 1958
Buku Teks
Lower, Arthur R.M.
Longmans, Green and Company, 1959
Buku Teks
Wagener, Albert M.
D. Van Nostrand Company, Inc., 1950
Buku Teks
Day, Arthur R
Wesview Press, 1986
Buku Teks