@article{SLC_1988_19_a15,
     author = {Michael Drmota},
     title = {\"Uber {Abz\"ahlprobleme} von unabh\"angigen {Teilmengen} in {B\"aumen}},
     journal = {S\'eminaire lotharingien de combinatoire},
     publisher = {mathdoc},
     volume = {19},
     year = {1988},
     url = {http://geodesic.mathdoc.fr/item/SLC_1988_19_a15/}
}