@article{ELA_2005__14__a4,
     author = {Britz, T. and Olesky, D.D. and van den Driessche, P.},
     title = {Schur complements of matrices with acyclic bipartite graphs},
     journal = {The electronic journal of linear algebra},
     pages = {2--11},
     publisher = {mathdoc},
     volume = {14},
     year = {2005},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ELA_2005__14__a4/}
}