Joseph Maier, Richard W.Weatherhead
F. A. Praeger, 1964
Buku Teks
Moore, John B.
Government Printing Office, 1906
Buku Teks
Seth, Michael, author
University of Hawaii Press, 2002
Buku Teks
Lindquist, John H.
Sage Publications, 1988
Buku Teks
Roberts, John D.
W.A. Benjamin , 1977
Buku Teks