\input zb-basic
\input zb-ioport
\iteman{io-port 03679782}
\itemau{Maksimova, L.L.}
\itemti{\"Uber eine Klassifikation der modalen Logiken.}
\itemso{Algebra Logika 18, 328-340 (1979).}
\itemcc{}
\itemut{superintuitionistic fragment; classification of normal modal logics; S4; clusters of Kripke-frames; finite model property}
\itemli{}
\end