@ARTICLE{
       Author = {Dimitropoulos, X. and Krioukov, D. and Fomenkov, M. and Huffaker, B. and Hyun, Y. and claffy, k. and Riley, G.}, 
       Title = {{AS Relationships: Inference and Validation}},
       Journal = {ACM SIGCOMM Computer Communication Review (CCR)}, 
       Volume = {37},
       Number = {1},
       Pages = {29-40},
       Month = {Jan},
       Year = {2007},
       Keywords = {routing   topology   policy}
}