\begin{thebibliography}{BOGW88}

\bibitem[BCW80]{ReadOnceBranching}
Manuel Blum, Ashok~K. Chandra, and Mark~N. Wegman.
\newblock Equivalence of free boolean graphs can be decided probabilistically
  in polynomial time.
\newblock {\em Information Processing Letters}, 10(2):80 -- 82, 1980.

\bibitem[BOGW88]{SecureMultiParty}
Michael Ben-Or, Shafi Goldwasser, and Avi Wigderson.
\newblock Completeness theorems for non-cryptographic fault-tolerant
  distributed computation.
\newblock In {\em Proceedings of the Twentieth Annual ACM Symposium on Theory
  of Computing}, STOC '88, pages 1--10, New York, NY, USA, 1988. ACM.

\bibitem[BRS91]{PPClosed}
Richard Beigel, Nick Reingold, and Daniel Spielman.
\newblock Pp is closed under intersection.
\newblock In {\em Proceedings of the Twenty-third Annual ACM Symposium on
  Theory of Computing}, STOC '91, pages 1--9, New York, NY, USA, 1991. ACM.

\bibitem[Sha79]{ShamirSecretSharing}
Adi Shamir.
\newblock How to share a secret.
\newblock {\em Commun. ACM}, 22(11):612--613, November 1979.

\bibitem[Smo87]{SmolenskyLowerBound}
R.~Smolensky.
\newblock Algebraic methods in the theory of lower bounds for boolean circuit
  complexity.
\newblock In {\em Proceedings of the Nineteenth Annual ACM Symposium on Theory
  of Computing}, STOC '87, pages 77--82, New York, NY, USA, 1987. ACM.

\bibitem[Tod91]{TodasTheorem}
Seinosuke Toda.
\newblock Pp is as hard as the polynomial-time hierarchy.
\newblock {\em SIAM J. Comput.}, 20(5):865--877, October 1991.

\bibitem[Val79]{ZeroOnePermanent}
L.G. Valiant.
\newblock The complexity of computing the permanent.
\newblock {\em Theoretical Computer Science}, 8(2):189 -- 201, 1979.

\end{thebibliography}
