Rowbottom, Darrell P., 1975-
Polity Press, 2015
Buku Teks
Whittle, Peter
John Wiley & Sons, 1970
Buku Teks
Billingsley, Patrick
John Wiley & Sons, 1979
Buku Teks
Laha, R.G.
John Wiley & Sons, 1979
Buku Teks
Kyburg, Henry E.
Prentice-Hall, 1969
Buku Teks