@ARTICLE{
       Author = {Kitsak, M. and Riccaboni, M. and Havlin, S. and Pammolli, F. and Stanley, H.}, 
       Title = {{Scale-free models for the structure of business firm networks}},
       Journal = {Physical Review E}, 
       Volume = {81},
       Month = {Mar},
       Year = {2010},
       Keywords = {topology   network geometry}
}