Oceana Publications, 1958
Buku Teks
Corwin, Edward S., author
Great Seal Books, 1955
Buku Teks
Stannard, Harold, author
Adam and Charles Black, 1949
Buku Teks
Nowak, John E., author
Thomson/West, 2010
Buku Teks
Mason, Alpheus Thomas,1899-1989, author
Prentice-Hall, 1993
Buku Teks