@article{ITA_1983__17_2_163_0,
     author = {Janssens, D. and Rozenberg, G.},
     title = {Hypergraph systems and their extensions},
     journal = {RAIRO. Informatique th\'eorique},
     pages = {163--196},
     publisher = {EDP-Sciences},
     volume = {17},
     number = {2},
     year = {1983},
     mrnumber = {713228},
     zbl = {0512.68062},
     language = {en},
     url = {http://www.numdam.org/item/ITA_1983__17_2_163_0/}
}