Juhl, P.D.
Princeton University Press, 1980
Buku Teks
Ryan, Michael, 1951-, author
Wiley-Blackwell, 2017
Buku Teks
edited by Julie Rivkin and Michael Ryan
John Wiley & Sons, 2017
Buku Teks
Cambridge University Press, 1997
eBooks
Bowie, Andrew, author
Routledge , 1997
Buku Teks