@TECHREPORT{
       Author = {Krioukov, D. and Papadopoulos, F. and Boguñá, M. and Vahdat, A.}, 
       Title = {{Efficient Navigation in Scale-Free Networks Embedded in Hyperbolic Metric Spaces}},
       Institution = {arXiv cond-mat.stat-mech/0805.1266},
       Month = {May},
       Year = {2008},
       Keywords = {routing   topology}
}