Hartley, John, author
Blackwell, 2008
eBooks
Cashmore, Ellis, author
Routledge, 1994
Buku Teks
with introduction by Harold Earl Hammond
Cambridge Book, 1964
Buku Teks
Metcalf, Franz, author
Berrett-Koehler, 2012
Buku Teks
John Wiley & Sons, 2009
eBooks