edited by Carmen de Jong, David Collins, Roberto Ranzi
John Wiley & Sons, 2005
Buku Teks
Greenwood, Ned H.
Duxbury Press, 1979
Buku Teks SO
Josef Krecek, editor
Springer, 2012
eBooks
edited by Levette Jay Davidson
University of Denver Press, 1951
Buku Teks SO
Parris, Kristen M.
John Wiley & Sons, 2016
Buku Teks