@article{SLC_1990_25_a15,
     author = {Reinhard Wolf},
     title = {Die {Rendezvous-Zahl} eines endlichen, zusammenh\"angenden {Graphen}},
     journal = {S\'eminaire lotharingien de combinatoire},
     year = {1990},
     volume = {25},
     url = {http://geodesic.mathdoc.fr/item/SLC_1990_25_a15/}
}