@article{SLC_1983_07_a1,
     author = {Achim Bachem},
     title = {New {Trends} in {Combinatorial} {Optimization}},
     journal = {S\'eminaire lotharingien de combinatoire},
     year = {1983},
     volume = {07},
     url = {http://geodesic.mathdoc.fr/item/SLC_1983_07_a1/}
}