Couto, Ricardo, author
Springer, 2012
eBooks
Lilly, J. Robert, author
Sage Publications, 1995
Buku Teks
Jacobs, Sydney, author
LBC Information Service, 2000
Buku Teks
Bix, Brian H., author
Sweet & Maxwell, 1999
Buku Teks
Reardon, Kathleen Kelley
Beverly Hills, 1981
Buku Teks