@article{SLC_2000-2001_45_a3,
     author = {Helmut Kr\"amer},
     title = {Binary {Moore-Penrose} {Inverses} of {Set} {Inclusion} {Incidence} {Matrices}},
     journal = {S\'eminaire lotharingien de combinatoire},
     year = {2000-2001},
     volume = {45},
     url = {http://geodesic.mathdoc.fr/item/SLC_2000-2001_45_a3/}
}