\input zb-basic
\input zb-ioport
\iteman{io-port 50230934}
\itemau{Wachs, Michelle L.}
\itemti{Obstructions to shellability}
\itemso{Discrete & Computational Geometry 22, No. 1, 95-103 (1999).}
\itemcc{}
\itemut{}
\itemli{doi:10.1007/PL00009450}
\end