\newcommand{\etalchar}[1]{$^{#1}$}
\begin{thebibliography}{BCD{\etalchar{+}}06}

\bibitem[BCD{\etalchar{+}}06]{Dotw}
R.~A. Bailey, P.~J. Cameron, P.~Dobcs\'anyi, J.~P. Morgan, and L.~H. Soicher.
\newblock Designs on the web.
\newblock {\em Discrete Math.}, 306:3014--3027, 2006.
\newblock \URL{http://dx.doi.org/10.1016/j.disc.2004.10.027}.

\bibitem[CDMS04]{Extrep}
P.~J. Cameron, P.~Dobcs\'anyi, J.~P. Morgan, and L.~H. Soicher.
\newblock {\em The external representation of block designs, Version 2.0},
  2004.
\newblock \URL{http://designtheory.org/library/extrep/}.

\bibitem[CS]{CaSo}
P.~J. Cameron and L.~H. Soicher.
\newblock Block intersection polynomials.
\newblock {\em to appear in Bull. London Math. Soc.}
\newblock Preprint available at:
  \URL{http://designtheory.org/library/preprints/}.

\bibitem[LN06]{GAPDoc}
F.~L\"ubeck and M.~Neunh\"offer.
\newblock {\em The GAPDoc package for GAP, Version 0.99999}, 2006.
\newblock \URL{http://www.math.rwth-aachen.de/~Frank.Luebeck/GAPDoc/}.

\bibitem[McK90]{Nauty}
B.~D. McKay.
\newblock {\em {nauty} user's guide (version 1.5), Technical report
  TR-CS-90-02}.
\newblock Australian National University, Computer Science Department, 1990.
\newblock nauty homepage: \URL{http://cs.anu.edu.au/people/bdm/nauty/}.

\bibitem[MS]{McSo}
J.~P. McSorley and L.~H. Soicher.
\newblock Constructing $t$-designs from $t$-wise balanced designs.
\newblock {\em to appear in European J. Combinatorics}.
\newblock Preprint available at:
  \URL{http://designtheory.org/library/preprints/}.

\bibitem[Soi06]{Grape}
L.~H. Soicher.
\newblock {\em The GRAPE package for GAP, Version 4.3}, 2006.
\newblock \URL{http://www.maths.qmul.ac.uk/~leonard/grape/}.

\end{thebibliography}