Skrob, Robert, author
Entrepreneur Press, 2011
Buku Teks
Saez, Eileen Elliott de, author
Facet Pub, 2002
Buku Teks
Rowley, Jennifer, author
Ashgate, 1998
Buku Teks
Saez, Eileen Elliott de, author
Facet, 2002
Buku Teks
Skrob, Robert, author
Entrepeneur Press, 2013
Buku Teks