\input zb-basic
\input zb-ioport
\iteman{io-port 05747163}
\itemau{Currie, James D.; Saari, Kalle}
\itemti{Least periods of factors of infinite words.}
\itemso{Rev. Inform. Teor. Apl. 43, No. 1, 165-178 (2009).}
\itemcc{}
\itemut{}
\itemli{doi:10.1051/ita:2008006}
\end