Sheptycki, J. W. E., 1960-, author
Avebury, 1993
Buku Teks
Weatheritt, Mollie
Croom Helm, 1986
Buku Teks
Business Innovations Center (BIC), 2016
Buku Teks
McColvin, Eric, author
Longmans, Green and Co., 1946
Buku Teks
Dutton, Michael R.
Cambridge University Press , 1992
Buku Teks