diff -r abeb2bd9233e -r 71ab1c23df2a pnas/pnas.tex --- a/pnas/pnas.tex Fri May 06 17:20:51 2011 -0700 +++ b/pnas/pnas.tex Fri May 06 17:21:26 2011 -0700 @@ -392,7 +392,7 @@ the TQFT invariant $A(Y)$ of a closed $k$-manifold $Y$ is a linear $(n{-}k)$-category. If $Y$ has boundary then $A(Y)$ is a collection of $(n{-}k)$-categories which afford a representation of the $(n{-}k{+}1)$-category $A(\bd Y)$. -(See \cite{1009.5025} and references therein; +(See \cite{1009.5025} and \cite{kw:tqft}; for a more homotopy-theoretic point of view see \cite{0905.0465}.) We now comment on some particular values of $k$ above.