by Robert Bartley [and others]
ISEAS, 1994
Buku Teks SO
edited by Pieter J.D. Drenth, Joseph A. Sergeant, Roelf J. Takens
John Wiley & Sons, 1990
Buku Teks SO
Jens Damm
VS Verlag, 2012
eBooks
edited by D.R. Rutter, and Lyn Quine
Avebury, 1994
Buku Teks SO
edited by Wim Stokhof, Paul van der Velde
Curzon Press, 2001
Buku Teks SO