Markus Maier Ulrike von Luxburg Matthias Hein Influence of graph construction on graph-based clustering measures. 1025-1032 2008 NIPS http://books.nips.cc/papers/files/nips21/NIPS2008_0738.pdf conf/nips/2008 db/conf/nips/nips2008.html#MaierLH08