@article{SLC_1983_09_a0,
     author = {Helmut Prodinger},
     title = {Abz\"ahlprobleme bei {B\"aumen}},
     journal = {S\'eminaire lotharingien de combinatoire},
     publisher = {mathdoc},
     volume = {09},
     year = {1983},
     url = {http://geodesic.mathdoc.fr/item/SLC_1983_09_a0/}
}