Barker, S. F.
Cornell University Press, 1957
Buku Teks
Mates, Benson, author
Oxford University Press, 1965
Buku Teks
edited by Dov M. Gabbay and John Woods
Elsevier, 2004
Buku Referensi
Tidman, Paul, author
Wadsworth, 1999
Buku Teks
Hurley, Patrick J., 1883-1963, author
Wadsworth, 1984
Buku Teks