%0 Journal Article %A Janssens, D. %A Rozenberg, G. %T Hypergraph systems and their extensions %J RAIRO. Informatique théorique %D 1983 %P 163-196 %V 17 %N 2 %I EDP-Sciences %U http://www.numdam.org/item/ITA_1983__17_2_163_0/ %G en %F ITA_1983__17_2_163_0