Cowan, Thomas A.
Oceana Publications, Inc, 1967
Buku Teks
Fersch, Ellsworth A.
Charles C. Thomas, 1979
Buku Teks
Duxbury, Neil, author
Clarendon Press, 1995
Buku Teks
Herget, James E., author
Texas: Rice University Press, 1990,
Buku Referensi
Herget, James E., author
Rice University Press, 1990
Buku Referensi