\input zb-basic
\input zb-ioport
\iteman{io-port 50329428}
\itemau{Schlimm, Dirk}
\itemti{Learning from the existence of models: on psychic machines, tortoises, and computer simulations}
\itemso{Synthese 169, No. 3, 521-538 (2009).}
\itemcc{}
\itemut{}
\itemli{doi:10.1007/s11229-008-9432-5}
\end