@article{KYB_1992__28_Suppl_a5,
     author = {Mattila, Jorma K.},
     title = {Modified modus ponens and modal logic},
     journal = {Kybernetika},
     pages = {28--32},
     publisher = {mathdoc},
     volume = {28},
     number = {Suppl},
     year = {1992},
     mrnumber = {1226047},
     zbl = {0861.03011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/KYB_1992__28_Suppl_a5/}
}