Krontiris, Tina, author
Routledge, 1992
Buku Teks
Grant, Patrick
Macmillan Press, 1979
Buku Teks
Wooden, Warren W.
University Press of Kentucky, 1986.
Buku Teks
Williams, Harold Herbert, author
Sidgwick & Jackson, 1918
Buku Teks
Campbell, Oscar James, author
Crofts, 1947
Buku Teks