Morris, J.H.C.
At The Clarendon Press, 1960
Buku Teks
Richard Crawford Pugh
St.paul Minn, 1993
Buku Teks
John E. Noyes
St.paul Minn, 1997
Buku Teks
Dickinson, Edwin D.
The Foundation Press, Inc, 1950
Buku Teks
Beamish, Paul W., 1953-, author
Irwin, 1997
Buku Teks