Fersch, Ellsworth A.
Charles C. Thomas, 1979
Buku Teks
Duxbury, Neil
Clarendon Press, 1995
Buku Teks
Herget, James E.
Texas: Rice University Press, 1990,
Buku Referensi
Herget, James E.
Rice University Press, 1990
Buku Referensi
Gerber, Scott Douglas
New York University press, 1999
Buku Teks