@article{SLC_1988_19_a7,
     author = {Walter Wenzel},
     title = {Matroidizing {Set} {Systems}},
     journal = {S\'eminaire lotharingien de combinatoire},
     publisher = {mathdoc},
     volume = {19},
     year = {1988},
     url = {http://geodesic.mathdoc.fr/item/SLC_1988_19_a7/}
}