Jillian R. Griffiths, Jenny Craven, editor
Facet Publishing, 2009
Buku Teks
Buku Teks
edited by Michael H. Whitworth
Blackwell, 2007
Buku Teks
Blau, Peter M.
John Wiley & Sons, [1973, 1973]
Buku Teks
Trulove, James Grayson
HarperCollins, 2001
Buku Referensi