\input zb-basic
\input zb-ioport
\iteman{io-port 50089826}
\itemau{K\"arki, Tomi; Harju, Tero; Halava, Vesa}
\itemti{Interaction properties of relational periods}
\itemso{Discrete Mathematics & Theoretical Computer Science 10, No. 1 (2008).}
\itemcc{}
\itemut{}
\itemli{http://www.dmtcs.org/dmtcs-ojs/index.php/dmtcs/article/view/630/2192}
\end