Yin, Robert K., author
Sage, 2003
Buku Teks
Taylor, Donald H., author
John Wiley & Sons, 1982
Buku Teks
Jin, Ma
springer, 1999
Buku Teks
Phillips, Christopher, author
Oxford University Press, 2016
eBooks
Chateaubriand
Vorkink-Van Hoeve, [date of publication not identified]
Buku Teks