Stefan Engeser, editor
[Springer, ], 2012
eBooks
Moustakas, Clark E.
Sage Publications, 1994
Buku Teks
Petri, Herbert L, author
Cengage Learning, 2013
Buku Teks
Schunk, Dale H., author
Prentice-Hall, 1996
Buku Teks
Reich, John W., author
Oxford University Press, 2016
eBooks