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